THE ARUP JOURNAL

I C i i

>-

SUMMER 1985

I i Vol.20 No.2 Summer 1985 Contents Practical matters decking plus a layer of edge trim occurred, Published by With traditional concrete construction the studs detached. The site test seems Ove Arup Partnership 13 Fitzroy Street. London W1P 6BQ there are practical aspects which, because crude but appears to be quite effective. THEARUP they are so familiar, are often taken for Large holes for lifts and such like are granted by the design team or left in the formed by the decking laid to suit with edge Editor Peter Hoggett capable hands of site staff and the trim all round. Smaller holes for services Art Editor Desmond Wyeth FSIAD can more conveniently be formed by JOURNAL Assistant Editor David Brown contractor. Similarly with composite construction there are many practical running the decking through, boxing out Leslie & Godwin, Farnborough, aspects but in contrast these should be prior to concreting, then cutting the deck by Mike Bonner and Terry Raggett considered by the design team. afterwards. Steelwork erectors are permitted to work Because of the timescale of erection and Ronald Stewart Jenkins: without all the safety rails required for the comparatively small quantities engineer and mathematician, general labour gangs. This is one involved, the contractor will generally be by Ronald Hobbs advantage in having the profiled decking looking to pour quite large areas of included with the steelwork sub-contract, concrete at a time. On Farnborough where The Merlin Hotel, 14 so that the erectors also lay the decking. the concrete was pumped and power- Perth, Western Australia, However safety rails will then be required floated, the contractor was aiming to by Keith Pollock before reinforcement fixing and concreting. concrete one floor per day in each wing. The spacing of shear studs should be a Although this was a little optimistic for the City site: Lovat Lane, 18 multiple of, or the same as, the decking rib first wing where a learning curve situation by Deborah Lazarus centres where the decking crosses the applied, he did achieve it for each of the last beam. Conversely where the decking is two wings. Farnborough Road office development, 20 parallel to a beam, it should be arranged so Conclusion by Svend Jensen and Peter Lunoe that the ribs are spaced equidistant about The Farnborough Office Development has the centreline of the beam clearly demonstrated some of the Site testing of the shear studs is very advantages which can be gained by using simple. A small proportion are bent over to composite construction in the right 15° from the vertical, usually with an odd circumstances: given the high standards length of scaffold tube. If a stud detaches, required, the building has been completed or a visual inspection shows any fractures quickly and at a relatively low cost. in the weld, then it is condemned. On this project we found that generally studs Credits welded through a single layer of decking Client: were all sound, whereas in the few places County and District Properties Ltd. where two layers of decking or a layer of Front cover: Leslie & Godwin building: main office entrance (Photo: Peter Cook: Designed by: Arup Associates) Architects: Back cover: Ronald Jenkins Scott. Brownrigg and Turner Fig. 8 Quantity surveyor: Roadway under west wing Banks. Wood and Partners (Photo: Ernie Hills) Services consultant: Leslie & Godwin, Fig. 9 Michael Aukett Associates Escape stair in wings Landscape consultant: Farnborough (Photo: Svend Jensen) Eachus Huckson Partnership Main contractor: Fig. 10 Costain Construction Ltd. Arup Associates View along south wing Steelwork sub-contractor: Group 5 (Photo: Ernie Hills) Octavius Atkinson & Sons Ltd. Mike Bonner V Terry Raggett

The brief The Leslie & Godwin Group commissioned Arup Associates in September 1978 for the design of an owner-occupied office building totalling about 9,500m2 at Farnborough, Hampshire. The brief required a mixture of deep and shallow office accommodation with lettable commercial space at ground floor level. Outline proposals were approved by Leslie & Godwin in December 1978 but because of reorganization within their company, the scheme was temporarily halted. In March 1980 ownership of the proposed building was acquired by the Imperial Group Pension Trust Ltd. who, through their agents Richard Ellis, amended the brief to one considered more suitable for a 4 speculative building. The office space was > to be of a constant width of not more than 18m which could incorporate enclosed offices at the outer perimeter and also capable of being subdivided into separate lettable areas of between 600m2 to 850m2. The dining area was required to cater for a total of 450 people in three separate sittings and was to be provided with separate coffee lounge and bar. The ground floor had to include the pedestrian right-of-way developed into an enclosed shopping mall with as much commercial lettable space as possible on each side. In addition, covered space for 20 cars was required as part of the site right angles to the web, this method is of Each step of the flight is formed from a audible range, the low frequencies can be great benefit wl-.ere beams are connected steel plate bent to give a 75mm deep tray, felt and there is a danger that they may to the stanchion from two or more which is then filled with normal concrete induce high or audible frequencies in some directions. after steelwork erection. This gives the final part of the building, even far away from the Stanchion splices were initially stipulated stair ready for carpeting. source. To combat this the roof plantroom as being to full strength of the section, For the semi-circular landings the primary has a floating floor made with an bearing in mind that most stanchions were steelwork is two 150mm square hollow independent, mesh reinforced concrete designed to 90-95% of their capacity and section members, welded to give a T shape slab cast on a metal decking, which is some a little more. The fabricator chose to in plan. The outer edge is a curved supported from the structural floor by splice stanchions 500mm above second 100 x 100mm angle, acting both as edge resilient rubber pads. Apart from acting as floor level, and proposed end bearing for former and structural member. Holorib a structural isolator the floating slab adds axial load with normal bolting/plates for profiled decking and concrete then to the general mass of the floor structure moment capacity. After inspecting his complete the landing on site, again ready and provides high frequency attenuation works and the quality of machining, we for carpeting. Corrosion and fire protection agreed to the end-bearing proposal. To The stairs and landings are simple in The question of corrosion protection of the assist him we also gave more specific concept and construction. What is not so steelwork was discussed with the client at design values for stanchion moments at his obvious is the care required in design and a very early stage and it was agreed that chosen splice locations, enabling him to detailing to achieve this. Stairs often throw although it was basically in a dry, internal minimize the bolting/plates requirements. up problems disproportionate to the environment some form of protection Stability amount of work in them, and the ones in should be provided. All the internal this building were no exception. For steelwork, apart from the top flange of For structural stability the cruciform beams to which shear studs are welded, building shape is very suitable. Diagonal example the secondary core landings lie outside the perimeter line of stanchions, has been painted with a two-pack epoxy bracing is provided for both directions in primer. In addition the members along the the central core and for the transverse giving a most distinctive feature to the final building. However, the resultant force perimeter, which are more likely to become direction in the escape stair cores, at the damp, were given an MIO barrier coat. end of each wing. The locations of diagonal eccentricities, at mid-height level on the stanchions, proved quite a problem. Some The superstructure was required to have a members had to be co-ordinated with fire resistance of one hour and for internal services ducts and doorways into the cores, specially-shaped brackets, fitting com• pletely within the stanchion flanges so as beams and columns this was achieved by a so each elevation of bracing is designed as vermiculite spray, Mandolite P20, and by an N-truss arrangement. To allow for any not to protrude either into the cladding zone or the stairwell, were the answer. fire blankets at the expansion joints. direction of wind loading, diagonal The external stanchions at ground and first members were designed both for tension Structure-borne noise and vibration The steel-framed structure, being lighter floor were encased in concrete, with a and compression, using square hollow 50mm mesh reinforced cover, after section steelwork. and generally more flexible with a lower damping capacity than that of an erection. Expansion joints are provided towards the equivalent concrete structure, is more inner end of three of the wings, at locations susceptible to vibration. However, As far as the deck is concerned a Restricted chosen to give simple detailing. To permit calculations indicated that the structural Fire Engineering Approach was adopted to longitudinal movement but provide response of the building is perfectly calculate the extra fire reinforcement transverse stability the joints were made as which, in addition to the A98 mesh in the satisfactory for normal office use. The office entrance was to be separate into two and, although the site was left over sliding joints with dowels in the concrete top of the slab, amounted to an 8mm bar in from the entrance to the shopping mall and from the Kingsmead development, it is the deck. Longitudinal stability for these wings Although most machines and items of plant the bottom of each rib, ie at 150mm to have a clear identity for visitors to the centre of focus for people entering the is provided by the spine beams and vibrate at frequencies well below the spacing. building. centre by bus or from the public car parks columns acting as moment frames. S3 84 to the south, and for motorists coming As the west wing stanchions rise clear up to Aug Sap Del tov Dec Jan Feb Mar Apt May The client also requested that special down the hill into Farnborough on the A325 the second floor, it was logical not to have Structure programme ! attention was to be paid to the problems of Set up site traffic noise and solar gain and to the long- from Aldershot. an expansion joint for this wing but provide Sill durance and excavate longitudinal stability to it from the central Concrete footings : Wingi term running costs. The Royal Aircraft Establishment is located core. Providing bracing to the wing in this Concrete lootings Central The site about three quarters of a mile away Drainage under building towards the south-west and low flying manner is also of benefit in the design of Norih&Wett South & East The site is one acre of level land with the the individual stanchions, because of their Erect sttel frame Wings — — northern boundary enclosed by the 5.0m aircraft pass quite close to the southern E iHI t steal frame Central South ft East boundary when they approach the runway. slenderness. Concrete superstructure floors Wings • a Mm high red brick wall of the Kingsmead Concrete superstructure floors Central Shopping Centre. Although predominantly The design Stairs Hoot finishes a two-storey development, it also includes It was clear that the new building would The concept of straightforward steel B. Slab. Welti an eight-storey office block and a multi• have considerable impact on its erection, concrete cast on permanent Concrete central area Ground floor slab storey car park which dominate the scale of surroundings because of the key position of decking and no propping, is carried the surrounding area. the site. We therefore decided that it should throughout the superstructure including Concrete casing to eiternel columns contribute an element of order and visual the stairs in the central core and at the end The site is bordered by roads on the other _FirtpfO0fmg spray tojeemi and internet columns interest to the undisciplined and rather of each wing. Fig. 9 shows a stair core three sides; the A325 Farnborough Road Curtain walling Support brackets drab character of the neighbourhood. during construction. runs parallel with the eastern boundary linking Farnborough, Aldershot and The solution we adopted was a four-storey Each flight is a shop-fabricated steelwork Farnham with the M3 motorway, and to the 'U'-shaped office building which closely unit, bolted on site to the landing beams. south are two extensive public car parks follows the southern site boundaries and which abuts a high brick wall to the north Fig. 5 and a large roundabout. A few isolated Cladding Corridor Cladding mature trees offer a little relief to the separating the new development from the zone Office zone zone Office zone zone Programme for the structural works predominantly hard, noisy surroundings. shopping centre. Fig. 6 An existing public right-of-way connected Because of the site environment and the the shopping centre with the bus stop on need to protect the office space from traffic Layout of typical bay the southern boundary and divided the site noise and solar gain, it was considered Fig. 7 essential to seal the outer perimeter and Typical cross-section through deck therefore to air condition the interior. This 305x102x33 U.B. 305 x 102 x 25 U.B. led to the structure and the elevation -e> Cladding: playing a major part in the environmental Mullions supported by brackets services design concept for the building. bolted to slab All office spaces have raised floors for the distribution of computer cabling as well as Aluminium slab edge former 190x 100 high shear studs electrical and telephone services and this stayed at intervals to decking single line on every beam floor void is used as the supply air plenum for conditioned air supplied through floor- n n n n n n njI n n n Fig. 1 mounted air diffusers. 203x203x46 U.C. 254x254x 73 U.C. Detail showing the double skin The outer perimeter of the offices is do do enclosed within a double skin elevation. it Fig. 2 The outer skin is totally glazed with bronze r 1 The south elevation overlooking tinted glass to provide consistent, easily the car park maintainable weather protection. This skin Fig. 3 -i—I Perimeter beam Secondary beam Spine beam is facetted so that its reflective surface Site plan 356x127 x33 U.B. 305 x 102 x 33 (or 251 U.R 356 x127 x 39 U.B. responds to variations in light and changes 7.5 m 6.0 m Fig. 4 of view. At first floor the skin projects to Office interior form a glass canopy over the pavement. The inner skin consists of both glazed and checked for a full plastic distribution and economic and it is also the maximum per• entrance hall, see Fig. 4. All stanchions solid panels which are interchangeable to the shear connector requirements for this mitted span under GLC regulations when here are concrete-encased and designed as suit varying office layouts. The 1m wide are then calculated. Where appropriate the adopting a Restricted Fire Engineering such. The encasement was most important space between through which the main air number of shear connectors may be approach to the decking. in reducing the slenderness ratio of these UJ ml supply ducts run, contains motorized reduced which effectively reduces the Figs. 6 and 7 (overleaf) show the structural columns. Venetian blinds with finely perforated concrete stresses and increases steel arrangement for a typical bay in the wings. By efficient design of the steelwork, both in blocks to filter sunlight to the interiors. stresses from the fully composite The secondary beams are 305mm deep UB the overall arrangement and of the The 'U'-shaped plan encloses a garden at condition. This is then followed by a sections and the primary beams 356mm individual members, the tonnage required first floor level. Main circulation at each number of serviceability checks to ensure UB s. all in grade 50 steel. The metal for the building was kept very low. The level is along the shorter garden elevation that the steelwork stresses under wet decking is Holorib with cold formed edge weight of steelwork members equates to * ftir • * Restarant with direct access to the open office concrete, short and long-term deflections trims in galvanized steel, strapped back to 35 kg/m2, a figure which compares very - PL -...-..ill. ,$M yya spaces. Enclosed offices are located along are satisfactory. the sheeting. The overall thickness of the I I — I I I I I I — I I I I I I favourably with other steel-framed the outer perimeter where they have their deck is 125mm with normal grade 30 buildings. own outlook and are not disturbed by the By elastic design the shear connector concrete. pedestrian route. These private offices are requirement varies along the length of the Steelwork connections While the general wing beams had an For the steelwork connections we followed Fig. 5 formed from glazed or solid partition panels beam but using plastic design the studs efficient balance of concrete and steel for the normal practice of showing the Section similar to those of the inner skin with can be placed at uniform spacing with the composite design, different considerations unframed glazing at high level fitting into proviso that a serviceability check must be structural requirements, in terms of design applied to many of the core beams. Loads grooves in the ceiling beams. At first floor carried out on the peak stud force at reactions and moments, on a specific set of were heavier because of blockwork walls garden level the main circulation route working loads. In this country a standard drawings, enabling the fabricator to design and screeded rather than modular raised connects the three office cores to the size and type of connector is almost and detail the joints to his own preferred floors. Services openings and lift shafts methods. The steelwork connections were " " "i J^LT—' dining area which is built against the brick invariably used, a 100mm high by 19mm reduced the composite action available Bar wall enclosing the garden on the north side. diameter headed stud made from low required to take the full beam reactions and Ill 1 1 -r-t— . H from slabs and, of course, the services Behind this wall are the bar and servery carbon St 37-3K mild steel to the German moments as we considered little engineers particularly wanted to maximize with the coffee lounge and kitchen on the Standard DIN 17100. The advantage of this contribution could be gained from the the zone available for themselves with a level directly above. is that the stud has good welding qualities, concrete of the composite section. consequent minimization of structural its general properties and installation As a rule secondary beams were designed depth. Judicious re-arrangement of beam The ground floor encloses a pedestrian mall requirements are well established and the as pinned each end, perimeter and spine layouts plus a little extra reinforcement of with commercial lettable space on both necessary equipment for site welding is beams as having partial fixity. The the critical areas enabled us to satisfy all sides and accommodates the main office readily available. The stud-to-concrete com• fabricator chose not to have bearing cleats the requirements. entrance, computer suite, covered car park, pressive force is dependent on the concrete but end plates for all beams, and designed stores and some of the mechanical and geometry between adjacent decking ribs Columns were designed to BS 449, typical a set of joint types following standard electrical plant. The office entrance is a and the concrete grade and type. internal stanchions being 254 x254mm UC principles. Secondary beam connections double height space which opens up to the sections and perimeter stanchions were entirely within the steelwork depth, first floor pedestrian route and allows One of our early studies was to investigate 203 x203mm UC's. On the north, east and primary beam connections utilized the glimpses of the shrubs and trees in the the steelwork arrangements for secondary south wings the cladding steps in 900mm depth available within the concrete zone. garden beyond. It is located to the east of beams at 2m, 2.5m or 3.0m centres. These below the first floor as can be seen in Fig. For those situations where stanchion web Fig. 6 the pedestrian mall and is separated from it spacings cover the practical range of spans 10, so the perimeter stanchions become stiffeners were necessary, he used web First floor plan by the central stair core. The loading bay is for the profiled decking; any greater external and are concrete-encased. On the thickening plates on the principles in the north-east corner of the plan with spacing would require temporary propping west wing the cladding runs across the developed in recent years and shown in the direct access to the goods lift which serves of the decking during concreting. Our study soffit of the second floor, giving the clear Constrado Manual of Connection Design. all the office floors and the kitchen at showed the 3.0m spacing to be the most double-storey height area in front of the By comparison with traditional stiffeners at second floor level. Although the building has a 'U'-shaped plan Fig. 1 it is basically a linear structure in which • - Site plan concrete ribs span between concrete beams. The surfaces of the ribs are painted Fig. 2 in the offices and are evenly lit by specially p Typical secondary core View from north-east designed luminaires. This has the effect of making the ceiling float and appear higher Fig. 3 than the actual dimension of 2.4m from xtent of Expansion joints Main entrance hall finished floor to soffit. The main stairs and t, rpof plant rDOm lifts are located at the centre of the 'U' with Fig. 4 escape stairs and toilets at the ends of Erection of steel each arm. Between the service cores on the frame three upper floors are constant 14.40m wide Central Cor (Photo: Costain) office spaces giving discreet lettable areas Balancing typical floor] of approximately 800m2. DOOl Major elements of service plant are accommodated in the high level plantroom which is located on the roof between the Fig. 7 central and eastern service cores. The Ground floor plan plantrooms connect to the space between

(Figs. 2-3 Photos: Ernie Hills)

Bypass duct

Return] Supply fan plant

Warm air Return riser return riser in core — » ——i i 1 ._t—

Warm air Cool a return duct iupply

Warm air outlet

Fig. 8 Fig. 9 Radial floor beams under construction Cross-section showing air distribution the inner skin and outer skin which is used fitting than by structural considerations, Human beings are remarkably sensitive to General description of the building steel sections, preparation and checking of for the distribution of supply air ductwork and could have been decreased vibrations and it wasn't too difficult to Farnborough Road The building occupies a prime site at the working drawings and the actual and for maintenance access to the glass significantly by taking advantage of the calibrate the RE's dentures with Arup north-east side of the Clockhouse fabrication, tender documents were issued and blinds. The ductwork has a bright red prestressing techniques finally chosen for Acoustics' swinging needles, thus avoiding office development Roundabout close to the centre of at the end of May. The lowest tender was stelvetite finish which can be clearly seen this structure. However, their effectiveness the need for constant electronic Farnborough. The site measures roughly submitted by Octavius Atkinson who were behind the glass skin. as 'concrete lamp shades' would have been monitoring. Architects: Scott, Brownrigg and Turner 150m by 140m and has a slope of 7m from appointed towards the end of July, 10 The bronze glass outer skin as well as compromised by so doing. There were three main areas where north-east to south-west. weeks before start of erection. projecting at low level to form a canopy is At an early stage in the design a decision vibration was a potential problem: The building, with a gross floor area of To speed up construction, the steelwork raked back at high level to enclose the was taken to prestress (post-tension) the (1) Domestic houses about 100m away Svend Jensen approximately 10,000m2, has a cruciform rises directly from the foundations plantroom on the roof. In order to resolve ribs for a number of reasons: where vibrations evoked the understand• plan shape (see Fig. 2). The central area and including the stanchions in and around the the junctions resulting from this geometry, Firstly the relatively wide span and single- able concern and natural suspicion of the Peter Lunoe two of the wings are five storeys high and basement. This allows the upper floors to Pilkingtons and Doulton Glass developed a bay configuration produced rotations at the householders. the two other wings, designed to have a be completed in the shortest possible time new system of glazing for the building columns which influenced their size so that key activities such as roof which is now known commercially as the These houses were surveyed before and Introduction roof garden, are four storeys. The central disproportionately to the axial loads waterproofing, curtain walling and PilkingtonPlanar System. Sheets of 10mm after piling operations. No damage was Concrete versus steel-framed construction area is the only part of the building to have carried. By prestressing the ribs and installation of services can proceed in bronze armourplate glass, 3.6m high x 1.8m found but one resident was particularly is an argument which has been going on a basement and it also has a substantial considering the tendon profiles, column parallel with the more time-consuming wide, are held in place against aluminium concerned because the vibration was for 50 years or more. The deciding factor is plantroom on the roof. The entrance hall in moments could be adjusted and were in concrete construction in the underground mullions by six 6mm diameter countersunk causing waves in his fish tank, and his fish generally cost, which depends not only on the west wing is double storey height and fact greatly reduced. By load balancing, the ducts and ground floor. stainless steel bolts. These bolts pass were beginning to look a bit sea-sick. prices of materials and labour but also partly open to allow cars to drive up to the long-term deflection of the ribs became Substructure and ground floor through pre-drilled holes in the sheets and changes in design criteria, technical main entrance (see Figs. 3 and 4). negligible and pre-cambering unnecessary. (2) A multi-storey building, with long span The site investigation showed approx• are connected to the glass by a system of development and new construction The main core is in the central area, with and relatively flexible floors, about 200m imately 20m of Barton Sands overlying specially designed gaskets and washers. There were further advantages to be gained techniques. smaller cores which house escape stairs away. Vibration was felt particularly at the Bracklesham Beds. Settlement calcula• Only the bolts at the top corners of each such as reducing reinforcement conges• and duct risers at the end of each wing. upper levels. Since the 1950s concrete has been the tions based on static cone penetration sheet carry the vertical load of glass, the tion, but more importantly, by stressing the The planning module is 1.5m and the wings obvious choice for medium-rise buildings in tests confirmed that it was acceptable to remainder being used solely to transfer tendons in two stages, the formwork and (3) The adjacent supermarket, against the UK but over the last few years steel has have the normal office width of 13.5m with found the building at high level in the horizontal wind loads to the aluminium staging to the ribs could be removed after which we were piling to within 3m. It was made a strong come-back. central columns dividing it into 6 and 7.5m Barton Sands with a safe bearing pressure mullions. This method of fixing allowed the about three days. This was particularly necessary to change the pile type within This is partly due to the current low, it could spans. The longitudinal column spacing is of 200kN/m2. glass sheets to be considered as separate important since the ribs are exposed and 12m of this building to a smaller diameter be claimed artificially low, cost of steel but 6m increasing to 7.5m adjacent to the plates which could be located in space to therefore required particularly high quality, driven pile with steel permanent lining tube. the most significant factor is the use of central area. For ease of construction, strip footings, achieve the required facetted angles, and expensive GRP moulds. The moulds were of Once again we used the vibration composite construction with metal sheet The external elevations are clad inCoolite running the length of the wings on the the gaps between were then simply sealed trough profile and, for ease of handling, monitoring equipment to enable us to find a decking. mirror glass which reflects 83% of solar column lines, were used instead of with gun-applied silicone sealant. The made in five sections from a one-piece reasonable driving technique. As luck master. Each set of moulds was marked to This form of construction is common in heat. The cladding is made with structural individual pads. Adjacent to the basement erection of the glazing proved to be would have it the 'wines and spirits' counter ensure their correct match on site, where North America and most of the develop• silicone double-glazed units and is claimed the strip footings were stepped down using relatively easy and the whole system was along the wall adjacent to our site. mass concrete. they were butted together and carefully ments which have taken place over the last to be the first project of any size in Britain provided a simple solution to what could Using the vibration monitoring equipment have been a complicated problem. aligned on the staging. They were then 10 years have been pioneered in the United using silicone bonding on all four edges. The basement is close to the water table we were able to observe that the The rear elevations of the offices, which bolted together using foam strip between States. These include techniques for The exposed columns have an aluminium and as the ground is slightly acidic, with Ph permissible vibration outlined inD/N 4750 face the garden, are sealed with a more the butting faces, but no tape was used as coincided consistently and reliably with a through-deck stud welding and also casing with polyester power finish. Solid values down to 4.5, an external membrane conventional system of single, clear, it was considered that this would draw barely perceivable excitement of the improvements in steel sheet profile with panels with similar finish are also used at was used to provide watertight conditions toughened, glass sheets in aluminium attention to the joints when the ribs were Advocaat bottles, which increased specially designed indentures to increase the secondary cores, alternating with vision and at the same time protect the concrete frames with solid, insulated spandrel finally painted. All post-tensioning noticeably with increasing vibration levels. the load-bearing capacity of the sheet itself panels of mirror glass. from acid attacks. panels at each floor level and at the roof. hardware, fixing and stressing was by PSC Asking the RE to stare at rows of Advocaat and improve the shear bond properties The building is fully air-conditioned with a The basement excavation was done in open VAV system using ceiling-mounted slot Motorized blinds are also provided on the Slabstress using one 7k/13 tendon per rib bottles for hours on end during piling between the decking and concrete. cut with steeply battered side slopes up to diffusers. Heating is provided separately by east and west segments of the elevation to with recessed live end anchorages located operations is admittedly an unusual Within the UK there is now a considerable 7m deep. When wet, the Barton Sands turn specially designed perimeter-mounted control glare from morning and evening in the external face of the outer perimeter request. However, it enabled him to meet interest in composite structures encourag• into slurry and the excavations were radiant panels where the piped water sun. beam. The tendons were fully bonded, of several 'interesting people' and he is now ed by CIRIA and Constrado who have therefore protected by polythene sheets services, together with electrical services, parabolic profile, and stressed in two well practiced in Zen and Kendo:- the 'Way published a number of design guides, and a system of drainage channels. are distributed through the raised access Structural design stages at three and 14 days respectively. of the Bottles'. standards and technical notes. The suspended slab over the basement is floor. The section drawing shows the principal 325mm solid reinforced concrete. The The fibreglass moulds were by Barnes Not all methods of measurement require Composite construction does offer a structure to be arranged as a single portal ground floor slabs in the wings incorporate Plastics and the superstructure subcon• number of genuine advantages but some of Within the 1.8ha site there is a circulatory frame, four storeys high. gauges and dials. underground ducts which carry air- tractor was Gleeson. the claims made on its behalf appear to be road system and parking for 333 cars It is built entirely of in situ concrete and It should be explained at this point that we conditioning and other services between overstated, particularly as regards capital arranged in terraces separated by planting. comprises ribs spanning 14.4m between It is worth noting yet again that where a were interpreting vibration readings in the basement and the secondary cores at cost, in our experience it is now standard The external works also include a number perimeter ring beams, which are in turn project contains some unusual aspects, accordance withD//V 4750 which contains a the end of the wings. procedure to compare steel and concrete at of retaining walls and a 21m by 11m shallow supported on circular columns at either these usually perform well since they are fairly arbitrary and very global set of figures the early scheme design stage and in pool, an architectural feature which There are a couple of structural features in 5.4m or 7.2m centres. The curved section of given the attention they deserve. In this for different building types. case the post-tensioning and construction recent exercises of this type we have, in doubles as a regulator for the surface water the main entrance hall. The staircase to the the plan has radii of 14.4m and 28.8m to the However, the main object of using this and alignment of the formwork all each case, found the concrete structure to drainage system. first floor gallery is a thin helical slab inner and outer ring beams respectively. equipment was twofold: be cheaper in actual construction cost. Contract and programme which, supported only at the top and The ribs are spaced at 1.8m intervals along performed smoothly, accurately and rapidly. Firstly, to record the effects of adjusting However, once the cost benefit of the From the start the client made it clear that bottom, curves through 180 degrees. As a the outer perimeter closing up to 0.9m the driving technique in order to minimize shorter construction period for the steel he was looking not just for a strict budget visual counterpoint to this stair there is a along the inner perimeter. Their depth was Substructure vibration, whilst still achieving reasonable frame is assessed, this picture can change. but also for a tight overall programme to 'water feature', a helical reinforced determined more because of their A water table about 1.5m below ground driving progress. Concrete and steel are of course not give earliest possible completion. concrete cantilever, with a water cascade integration with the lighting/extract duct level, Ph values typically around 3.5, and a Secondly, as a public relations exercise so directly interchangeable; each project must Scheme designs started in January 1983. and planting. The formwork for both these site overlain by nearly 1m of peaty clay that all the 'interested' parties could see be considered individually as the general The studies of concrete and steel options structures, which can just be seen behind / ensured that the substructure required that we were taking the problem seriously. form of the building and choice of structure quickly showed that a composite steel the curved glazing in Fig. 3, was quite some thought. For some reason most people seem are interrelated. Composite construction structure would result in a two months complex and the contractor made a very The subsoil was basically silty sand peculiarly reassured by the sight of will offer maximum advantage if the saving in construction time and that the good job of the construction. overlaying gravels and because of the close someone with a box full of dials, aerials, following situations apply: financial benefit of an early completion Design of the superstructure proximity of existing buildings we would headphones, etc: the technological witch• completely outweighed the additional cost (1) Rectangular plan layout with repetitive At the time we did the design the composite have considered flight augered, grout doctor, but still, the techniques proved of the steel structure. elements beams/profiled metal decking method of intrusion piles (eg: Dowett Prepakt) had it valuable and successful on both counts. The site start was fixed for 15 August 1983 (2) No (or very small) cantilevers building was still very new to this country. not been for the acidity of the ground. We with a 65-week contract period. To get a Consequently up-to-date design methods Services (3) All steelwork within the external finally opted for driven in situ end bearing contractor abroad at an early stage a were not yet covered by British Standards. cladding to avoid concrete encasement piles with rigid PVC tubes encasing the Air conditioning Preliminary Enquiry Document, fairly We based our design on the 1983 CIRIA shafts. This at least seemed to provide a (4) Lightweight curtain wall cladding which The underfloor air conditioning system, similar to a Bill of Approximate Quantities, Report Composite construction using 1 solution to the ground water and acidity using the raised floor as a supply air can be erected without scaffolding was prepared in March and this formed the profiled steel decking. This document is I problems, but raised another problem- plenum, was designed for an adaptable (5) Finishes of dry construction which can basis for appointing Costain Construction supported by various research data and vibration. open plan office which can respond to the be put up quickly Ltd. as main contractor. During the design technical articles, particularly as regards The appointed piling sub-contractor, rearrangement of rooms and internal heat process Costains were involved in the shear studs/concrete interaction, and is (6) No severe height limitations (for spans Frankipile, had piled the adjacent site sources without major modifications. planning and programming, advised the generally in line with the ECCS European in the 6 to 7.5m range the structural without undue vibration problems, but A program was developed to analyze the design team on constructional aspects and Recommendations. floor depth increases by about 150mm monitoring during our trial pile test room thermal dynamics, taking into attended meetings with prospective sub• when compared with flat slabs). Full plastic design is used for checking indicated that we would have to modify the account the large thermal capacity of the One building, where most of those points contractors. ultimate strengths, with partial safety driving techniques in order to limit ground- concrete areas presented to the space by were fulfilled and where the comparison Fig. 5 shows the construction programme factors for loads and materials similar to borne vibrations. This was accomplished by the structural ribs. As the heat gain to the L. clearly favoured a steel structure, is the for the structural work in a slightly those in CP110. Using the 'partial- reducing the mandril drop at various stages office space reaches a peak during the day recently completed Farnborough Office simplified form. Erection of the steelwork interaction' method of design as described Fig. 10 during driving, whilst Arup Acoustics moni• the resultant temperature swing is limited Development for County and District was planned to commence seven weeks in the above CIRIA Report, the ultimate Plantroom at roof level tored the effect upon vibration at various by heat transfer to the cooler concrete Properties Ltd. after site start. To allow for the ordering of steelwork and concrete stresses are first locations using their magic black boxes. which reduces the capacity required from Ackermann electrical floor outlet , open the cooling system. This heat is later Electrical services rejected back into the space as the The continuous air handling luminaires Fig. 3 temperature tails at night and in the early located between the ceiling ribs in office morning. The computer program predicted areas were specially designed for the View up Lovat Lane that a constant supply air temperature of building and developed with Thorn EMI. Fig. 4 18.5°C with a constant supply air volume of They provide an average 600 lux at working six changes in the worst zone would plane and also evenly light the whole of the Building 'D' maintain a maximum dry resultant ribbed soffit. Fig. 5 temperature of 22°C at 1.5m above floor The luminaires have continuous fluor• Building 'AB' with terracotta facade level. A maximum temperature in the return escent tubes with white cross blade louvres and 'onion' dome air duct of 28°C was anticipated. below a continuous extract duct which is Fig. 6 Subsequent monitoring of the building's triangular in section. On both side faces of Stonemason at work on plaque, drawing environment has proved the accuracy of the duct are finely perforated metal panels attention to weathervane on Building 'AB' these predictions and confirmed that no with absorbent acoustic backing to limit j room terminal controls are required to cater the amount of sound which is reflected for the repositioning of the outlets to of the original after a protracted battle with back into the office space. The amount of provide a new load pattern. A sophisticated the planners to demolish the latter, which air extracted from the space can be varied control system is. however, provided to the was in extremely poor condition and which along the full length of the duct by opening central air handling plant to utilize outside we concluded was unstable: this was the or closing regularly spaced outlets. air and evaporative cooling whenever so-called 'Terracotta Facade' and the new Segregated mains with through wiring possible. wall is also partly faced with terracotta facilities are provided as well as 300mm/8W blocks, copied from the originals, which are emergency lamps, inverters and control The air handling plant for the offices is particularly attractive. gear fed from a central battery. The located at roof level and is divided into four Lovat Lane itself is a very narrow luminaires are block switched from the systems, each serving approximately one pedestrianized street, where individual service cores to ensure that the ceiling is quarter of the total office requirements. The elevational features perhaps have a greater evenly lit, allowance for future subswitch- main insulated supply ducts drop down in impact rather than entire buildings, due to the space between the two glass skins of ing is also included at the client's request. the limited perspectives which are possible. the southern elevations and connect to the The main office pedestrian circulation floor void plenums at each level. routes are lit by continuous suspended The concept of the City Village has tubelights which follow the curve of the attracted a certain amount of comment in Air is supplied to the office space through building and illuminate the concrete soffit. the national and architectural press, not all Krantz twist air outlets which can be shut These fittings were also specially designed of it favourable, but the development is at down if they are not required or relocated and include emergency lights and low least established on the map in when the offices are rearranged. voltage dichroic spots which highlight the consequence. Air is extracted through ducts integrated concrete columns. with the luminaires and passed to header Conclusions ducts within the raised floor above, which The main electrical power telephone and The four phases of City Village were in turn connect to the main air risers in the VDU services which rise in the stair cores completed in almost exactly four years when Building M was finished in May 1985. service cores. distribute horizontally within the raised The cost will be somewhat in excess of Extract air is recirculated or exhausted in floor void to a grid of fixed junction boxes. £10m. excluding land purchase costs. varying proportions at the dictate of the From these boxes flexible cable control system. The recirculated air is connections are made to multi-service Schemes are currently being examined for Ackermann floor outlets which can be upgrading one of the original either mixed directly with outside air or hence of the site. It was decided that bored delayed the Phase 3 contractor, Wates rearranged to suit new furniture layouts refurbishments, partly as a consequence of bypasses the evaporative cooler to achieve pile foundations were suitable and a Construction Ltd., from erecting when alterations are made. comparisons made with the new buildings the required air condition supply. system was developed to cater for the scaffolding in the same narrow lane for This ability to move the electrical and air by potential tenants. Outside air is normally introduced into the eccentricity of load using tension piles. In Building AB. supply outlets proved to be a considerable We found a straightforward structural air handling units through louvres in the most cases three piles were used at each Phase 4 was again negotiated with Trollope advantage during the fitting up period when solution to suit the particular constraints of roof plantroom walls but in the winter when column, with a single pile in tension. and Colls to gain a further time advantage office layouts were amended right up to the the development and we were content to solar gains and office heat losses warm the A pre-contract trial pile was specified for in completing the entire development; this time the building was occupied. retain it after a satisfactory trial on Phase 1. air in the double glazed void, the outside air the first phase with the results also being enabled an earlier start to be made as an is taken from this space to reduce the air used for Phases 2 and 4. On Phase 3 an overlap with Phase 2 could be achieved. This had obvious advantages and left us handling plant loads. In the summer when increased factor of safety was used (2.5 JCT '80 was also used for this contract but with relatively more time to concentrate on warm air in the double glazed void would instead of 2.25) to avoid the need for a with all sub-contractors taken on as the particular problems of each phase, increase heat gains to the office space, the further test; it was calculated that the cost domestic. This seems to be becoming an such as the deep underpinning on Phase 3 void can be ventilated by opening louvres in of the resulting additional length of each and the extreme lack of verticality of the Summer gap Winter solar increasingly common client requirement the plantroom wall to encourage air exhaust damper! handling preheated pile would be less than that of a test, and and presumably one which causes some Phase 4 party walls. We also found that on movement by 'stack effect'. These louvres outside additionally would not affect the misgivings to the Joint Contracts Tribunal, all phases the structure was completed also open automatically to ventilate the programme. bearing in mind the numerous and lengthy with few problems and, where not affected cavity if smoke is detected. nternal skin -glass or Contract arrangements clauses on nomination in JCT'80. by circumstances beyond our control, partition panel Heat loss at the perimeter is offset by ahead of programme, which really speaks Ventilation hv Phases 1 and 2 were carried out under the The development for itself. finned convector radiators fed from the stack effect 1963 RIBA Form of Contract. In order to Those buildings which have been in summer compensate temperature heating system obtain some appreciable degree of overlap refurbished tend to be fairly plain, with Credits: and controlled by thermostatic valves. The between the two contracts on adjacent brick facades unadorned by the features perimeter areas are protected from Blinds in gap between sites sharing the same limited access, the Client: glass skins controlled which characterize the new City Village Guardian Royal Exchange Assurance excessive heat gains by motorized Venetian automatically by sola Heat absorbing Phase 2 contract was negotiated with buildings. They are however obviously not blinds activated by solar radiation: The glass operates as Trollope and Colls Ltd.. the contractor on unrepresentative of the original character Architect: solar collector The Thomas Saunders Partnership louvre blades are perforated for about 20% in winter and Phase 1; the latter contract had been of the area and they do possess a certain of their area and so appear transparent sun shade in awarded on the basis of a conventional elegance. The new buildings are more Quantity surveyor: summer Wicksteed. Son & Few rather than opaque and allow views to the A.tifi ,i i tender. ornate, with extensive use of stonework, M&E consultants: outside without a major heat gain problem. Phase 3 was again put out to tender, this copper cladding on roof features and Cool air inlet The Williams Sale Partnership The blinds are lowered at night and during Supply time using the 1980 JCT Form of Contract, external metalwork. The most striking Buildings D.R.S, and AB weekends in the winter months to minimize on the basis that this was a separate site building is AB. which has an octagonal Max Fordham & Partners heat loss from the office spaces. tower on the corner of Lovat Lane and the construction would not affect any Buildings Q and M As a guide to energy use the building has rights of access, etc.. granted under Phases surmounted by a tower of reconstructed Main contractor: an office area of 8,250m2, a boiler output of Outside air inlet stone topped with a copper-clad dome and 1 and 2. In the event the reverse situation Trollope & Colls Ltd. a weathervane in the form of a fishing boat. 700kW, a chiller capacity in the region of occurred: Phase 2 was completed Buildings D.Q.R.S&M (Phases 1.2&4) Part of the Monument Street facade has 400kW and maximum electrical demand of considerably behind programme and the Wates Construction Ltd. 500kVA. scaffolding to the Lovat Lane elevation also been constructed as an exact replica Building AB 19 constructed in four phases. The phases areas of very limited headroom and City site: were to be overlapped as far as was restricted access. Lovat Lane practical, allowing for the extremely The new buildings were all designed to confined sites, their relative positions and maximize available lettable area on infill the lack of access. Two buildings were Architects: sites. The client required all new constructed in each of Phases 1 & 2 (D&Q The Thomas Saunders Partnership construction to be tight to the adjoining followed by R&S), with Building AB buildings and internal columns to be used constructed under Phase 3 and M under only if essential. With one exception the Deborah Lazarus Phase 4, buildings have six storeys including a Geology and site conditions single basement and they range in size A site investigation comprising four from approximately 440- 1720m2. We Introduction boreholes was commissioned in 1974. The adopted a basic scheme for the Phase 1 The Lovat Lane Conservation Area covers information obtained was supplemented by buildings and used this, with modifications the group of narrow streets to the west of two additional investigations, each where necessary, on the subsequent the Monument, due north of Billingsgate. comprising a borehole and various trial phases. A reinforced concrete framed This is the area which until about 10 years pits, in 1981 and 1982. structure with coffered, two-way spanning ago housed the fish merchants'offices and The geological succession is generally fill slabs was used, with lateral stability stores in buildings dating back generally to overlying gravel above the London Clay. provided by reinforced concrete walls to the the latter part of the 19th century. The Varying conditions are encountered, cores. In general the cores were located, at history of the area goes back a good deal however, due to the slope of the area least after consultation, to assist with further, with medieval remains uncovered towards the river. In particular the site at keeping spans to a size consistent with the attributable to the town house of the the bottom of Lovat Lane differs somewhat depth of slab selected without the need for abbotts of Waltham. A fine Wren church in from those further up. The properties of the internal columns; in one instance only, St. Mary at Hill dates back to 1670 and is clay are slightly different and persistent Building AB, this was not achieved; To held to be one of the most interesting bands of claystone were encountered maximize the coffered areas of slab in the among those remaining. irregularly shaped buildings, a 600mm during piling. In the early 1970s we were appointed by waffle was chosen rather than the more Structural schemes Compass Securities with the Thomas common 900mm module. Storey heights Saunders Partnership as architect to advise A variety of construction materials was were selected to suit the existing buildings on the development of the area for offices. encountered and indeed used during the and the slope of the lanes and the slab The brief initial phase of refurbishment. The majority depth then tended to be determined by the of the floors were timber while vertical required clear height and depth of false The original intention was to demolish most elements were steelwork or load-bearing ceiling to suit air-conditioning ductwork. of the existing buildings and to construct brickwork. Where loads were increased or one 'mega block' which would bridge new elements of vertical structure The layout of the buildings was not felt to across Lovat Lane, from Botolph Lane in introduced, new foundations were required be suitable for a raft foundation and the west to St. Mary at Hill in the east (see and underpinning of existing wall footings shallow pad footings would have been Fig. 2) This was rejected, perhaps not was necessary where basement depths uneconomically large due to the surprisingly, by the City planners, and our were increased. Bored piles were installed eccentricity imposed by keeping all vertical work at this time consisted essentially of loads at the perimeter of the building, and major refurbishment of individual units. in several instances, generally working in Schemes were complicated by the Fig. 1 requirement both to retain several listed Building 'R': facades, and to avoid the payment of part elevation: Development Land Tax in virtually all cases. (Drawn by This latter restriction related in part to the Colin Barnard) proportion of new floor area which was permitted; where existing floors were retained in consequence, the available headroom was often low and did not allow the introduction of significant service zones. Work effectively ceased in 1978 with a number of buildings remaining vacant and semi-derelict. In 1981 the development had been taken over by Guardian Royal Exchange Assurance and the concept had changed to that of the 'City Village'. The brief was to redevelop the derelict buildings as small, high quality offices and the planning consent was based on a series of ornate and complex elevations which would re-create original features from the surrounding area. Fig. 2 Six new buildings were required, to be Site plan

New construction Refurbishment

Botolph Lane mm

Lovat Lane Son Rut; i Qui P 4

SI Ma,, al

18 Costs The building provided a gross area of 9,500m2 of which 8,250m2 was office space completed to good quality property developers, standards with raised floors and carpet throughout. The total cost of the building was £7m. for which we were directly commissioned by Leslie & Godwin. An additional £2.5m. was spent on fitting up the interior. This included the fitting up of the restaurant, kitchen, bar, computer room and offices as well as a complete range of new furniture for the whole building. Start on site was delayed by two months but apart from this, the building was completed to programme and was within r the budget. \

Reflections in the bronze glass outer skin and below: the main office entrance

Programme

Arup Associates commissioned by Leslie & Godwin September 1978

Outline Proposals approved by Leslie & Godwin December 1978

Outline Planning Permission January 1980

Imperial Group Pension Trust Ltd. became client March 1980

Revised scheme design approved by Imperial June 1980

Detailed planning permission November 1980 Access to the offices is through possible, and went from the start for 'fast octagonally-shaped load-bearing brick stair tracking' with design proceeding in parallel Laing Management Contracting Ltd. cores located around the site. The stairs to with construction. We made extensive use appointed these cores, and the hotel fire escapes, are of our in-house computer and suite of June 1981 constructed of prefabricated steel with an OASYS structural computer programs to Start on site upturned 'U' shaped tread. The steel stairs assist in producing the documents ahead November 1981 were installed early in the programme to of programme. allow temporary access; later the treads Now completed, the development has Building hand-over were filled with concrete to provide a per• already established an identity in Perth and February 1983 manent (less noisy) final product. is proving popular with both hotel patrons Multiplex required the building as soon as Interior design and and general public alike. fitting out contract completed Credits August 1983 Architects: John Andrews International Pty. Credits Client: Client: Withernsea Pty. Ltd. Imperial Group Pension Trust Ltd. Main contractors: Multiplex Contractors Pty. Ltd. Designed by: Quantity surveyors: Arup Associates Rider Hunt and Partners Main contractor: Services consultants: Laing Management Contracting Ltd. Matthew Hall Pty. Ltd. PAiofos: Photos: Peter Cook Harry Sowden Crispin Boyle Arup Associates The brickwork has a design compressive strength of 50 MPa maximum, varying to 30 Two papers late in his life and published in MPa at the lower floors. The tops of the Ronald Stewart Jenkins: the Memorial Issue of The Arup Journal brick walls have slip joints with neoprene deal with such subjects: Towards a sliding bearings at the underside of the engineer and mathematician Variational Method for the Static concrete roof level to accommodate Equilibrium of Curved Bodies and Shells differential movement. The lift, stairs and and Membrane Theory in General Co• service cores at the intersection of each of Ronald Hobbs the four hotel wings are 200mm thick ordinates by Matrix-Tensor Methods. I am not aware that this work has led slipformed concrete. These walls take the This talk was given to the History Study Group of the anywhere - perhaps the computer which majority of the lateral design forces for the Institution of Structural Engineers at Imperial College on 16 December 1982. building. does not admire elegance has made them unnecessary - but I am sure that if Ronald The level 6 hotel accommodation level is a Introduction undoubted elegance. Ronald attacked most had been able to develop them, our 1.5m thick beam and slab structure Perhaps the best example I can give of problems as elegantly as possible; in understanding of complex three- transferring the hotel typical loadbearing Ronald's approach to his subject is the day solving a statically indeterminate dimensional shell structures, thick or thin, brickwork to the 9.0m column grid of the he came to the office with his completely framework he would spend much time in would have been greatly increased. basement carpark. The services from upper general definition of n-dimensional strain. choosing the necessary cuts and releases Ronald, of course, was not one of this level bedrooms pass down to the underside Most engineers, for obvious reasons, begin in order to make the resulting equations as world's natural, easy, communicators. of level 6 slab and then travel laterally by making a maximum number of well-conditioned as possible. through the beam structure to exit ducts. approximations or assumptions; Ronald All this is perhaps summed up in a well- Anyone reading-if 'reading' is the right always preferred to approach problems as loved and much polished summary in word - Cylindrical Shell Structures can see Atrium generally as possible and build in the Chapter 8 of The Theory and Design of that, but by the time you understood him The atrium roof is constructed of a series of necessary assumptions which flow from Cylindrical Shell Structures: and what he was driving at, it stuck for ever. steel transparent Lexan -clad arches, real life as late as possible. meeting in the centre of the hotel at a 'When matrices are used we obtain the You would also appreciate the This was the mathematician showing square gridded space frame. All the symmetric form as a geometrical con• mathematical elegance of all his work. through. steelwork uses standard tube or rolled sequence, without appeal to the concept One example is an equation in the book on sections and welded and bolted I should also like to quote from Ove Arup's ion of work, which is merely the name of cylindrical shell structures. In one line a connections. The hotel roof, the front introduction to RSJ's book The Theory and a scalar invariant associated with contra- multiplier in a matrix equation is given as entrance canopy and the rear podium Design of Cylindrical Shell Structures: gredient sets'. L= A little later the same equation canopy are of similar construction. The 'It would, however, not be advisable-or I am sure that today's very young students larger rear canopy is a 60m long x 20m wide even safe-to employ approximate of 'New Mathematics' would appreciate 2 ST triple-vaulted tubular-framed structure. The methods in all cases. They ought to be that. begins ^^ • On being asked by one subcontract for the steelwork to these roofs employed only by designers experienced in One of the tests of Ronald's concepts came was approximately $1.5m. the application of the complete theory.' immediately after the War with the eminent engineer to explain, Ronald was Ballroom roof Ronald, however, was essentially an introduction of prestressing to statically puzzled; he was, after all, only solving a set The ballroom roof forms the external deck engineer, and his meticulous attention to indeterminate structures. The calculation of differential equations, and reversing that to the 20m long swimming pool. The roof engineering detail-where the reinforcing of the so-called parasitic stresses was particular multiplier merely changed the spans 26m across an octagonal 6m high bars actually went in the concrete-was a taken in its stride by this concept. It also value of the arbitrary constants. So why the space with a grillage of beams and slab. by-word to the few people who had worked naturally dealt with forces created by question? The beams to the ballroom roof are closely with him. temperature and shrinkage. Jenkins the man perforated for a depth of 500mm below slab I first met RSJ in late 1948-a client had Nowadays we all, or almost all, use Ronald as a man was difficult to know at level, in one direction, to accommodate recommended to Ove that he take me on, computers, large or little, for all first, essentially shy, which was sometimes services. A 2-stage in situ beamlBondek and I suppose he felt that if I saw all the calculations. When I first met Ronald he mistaken as aloofness. slab construction method was devised to partners one would come up with a good was using a hand-operated Facit for the An example of this, and one of my favourite allow the ductwork to be fixed from the reason why they shouldn't. Anyway, I solution of 8 x 8 and larger simultaneous memories of Ronald, is the time two now upper level prior to pouring the slab. The joined, and after a couple of months, equations, using Fox's method for inverting eminent services engineers came to visit design also included provision of two started work with Ronald on various a matrix. Computers chew up equations him. I found them wandering around and adjustable universal column temporary buildings in the Festival of Britain. and spit out the answers without tasting sat them in his office to wait. I went away to them at all-but maybe that's just props to allow delaying infill of the 4.5m Statically indeterminate structures do some work, came back an hour later: nostalgia for the heady post-War years. square crane opening which also existed At that time my knowledge of the solution they were still there, no sign of Ronald, so I He was, however, at a very early time through the ballroom area. of statically indeterminate structures said 'Well, what happened?' The facade of the hotel is a combination of rested on a confusion of Hardy Cross and acutely aware of what computers could do 'Well', said the visitors, 'he came in, sat at face brick and precast concrete spandrel strain energy. for us. His contribution to the 'Dome of his desk and he started doing some work.' units. The precast units vary in thickness Discovery' paper at the Civils in 1952 Ronald very quickly introduced me to Now, it was nearly impossible to interrupt from 100mm to 180mm and were made on brought from one of the authors a matrices, via Aitken's little book and his Ronald when he was actually doing some site in steel forms set up on the podium question - What are digital computers?- own adaptation of influence coefficients calculations. 'And,' they said 'a little later slab at level 3. Temporary shelf angles held but it must be remembered that it wasn't using matrices. He managed to condense he got up, and he put on his coat and he the spandrels in position and allowed until one year later that IBM entered the the whole subject of statically went out.' I asked him the next morning, adjustment until an in situ concrete stitch computer field! Computers have taken the indeterminate structures to three very short drudgery from arithmetic calculations, but and he said 'Oh dear. I'd forgotten. I was poured for final support. lines-that is my memory: John Henderson also possibly have taken some of the joy thought they were the auditors!' We had a The hotel is linked by stairs and escalators says half a page! This, padded out a bit, and pleasure from analysis. I also think that habit in those days of lending out his office to a series of external courtyards, plazas was given as a paper to the Euler Society in it was a great pity that RSJ became to the auditors once a year so they could and arcades which are located at level 3. 1953, after being refused by the Institution seriously ill before computers had caught check whether we were making a profit or The structural slab form of the car park of Civil Engineers as being either (a) too up with him! not. below this level is repeated for these areas, easy, or (b) too complex. The complete However, through his work he formed with adjustment to support extensive paper is, I believe, only published in the Shell structures several unusual and lasting friendships. For landscaping, planting and precast paving. Ronald Jenkins Memorial Issue oiThe Arup The other great interest in Ronald's example, with the contractor engineer, the The plaza slabs were constructed in a Journal. late B.H. Broadbent, and the architect Peter sequence incorporating control strips professional life was the 'third dimension'. It had long been clear that Ronald had Many engineers and unfortunately quite a Smithson - two entirely different people between expansion joints at 60m centres to considerable ability, but it was not until fire- few architects are two-dimensional men, but who both intuitively understood that allow for concrete shrinkage and thermal watching during the War that he ran into and it is a mark of the great engineer or Ronald's appreciation of the part structures movements. matrices and realized what a powerful tool architect, his understanding and use of the play in buildings went far deeper than The shopping arcade has 40 retail they could be, coupled with Ostenfeldt's third dimension. To me at least, Ronald's merely his mathematical ability to solve tenancies to serve both hotel patrons and influence coefficients, to which, in the understanding of the third dimension was complex problems. To me, nowhere was general public. Additionally, the centre original Danish, he had been introduced by virtually complete and quite intuitive. this more demonstrated than in incorporates a health club, squash courts, Ove Arup some time before-they were Outwardly, this is perhaps best shown in Hunstanton School, a simple project-as and a service station at the entrance to the both working for J.L. Kier at the time. his interest in, and work on, shell simple as the Smithsons could afford to car park. John Henderson will no doubt remind us structures. make it-but where in the course of its solution Jack Zunz and I learned virtually Offices graphically how he just happened to By the time I met him, RSJ had already everything there was to know about the The offices from level 4 to level 7 wrap introduce matrices to Ronald Jenkins one published Cylindrical Shell Structures and plastic theory at that date-and still the around the plaza areas on three sides of the night; an introduction which I feel sure that was well on the way to an enduring and building stands up! project. The 9.0m diagonal column grid John will agree has been amply repaid, not increasing interest in the mathematics of extends through from the car park and to mention the teaching of later engineering; towards the end of his career Looking back over 35 years, and certainly supports the flat plate concrete floor slab generations of Imperial College students. this was taking him into esoteric and on reading RSJ's published works, one and roof structure. The columns are set The whole concept of statically in• rarefied atmospheres where few could might be excused for thinking that here was back from the facades giving mullion-free determinate structures set out by Jenkins follow-I, for one, was only happy at a theoretical engineer bemused by glazing and 12m open plan office spaces. had an immediate appeal because of its ground level. mathematics for mathematics' sake. This Parking for 1,000 cars is accommodated table level encountered during the spears were used in the north sandy strata over two basement levels covering the total geotechnical investigation, foundations and sumps, wellpoints and drains in the area of the site. The lower basement, were selected along with recommendations clay to the south. The slabs interconnecting accessed through the car park by ramps of improvement procedures where the pad footings were designed for uplift from the southern entry, is at R.L.-1.70 unsatisfactory ground may be encountered. pressures which were controlled by the with an upper basement level at R.L. 1.30. The 13 storey hotel tower to the north of the inclusion of a grid of pressure relief tubes Site investigations were carried out to site is founded on a 1.5m thick raft with a cast into the basement. enable assessment of suitable foundation ground bearing pressure of 150 kPa. The systems for the hotel tower, the podium The car parking floor structure is a upper levels of the hotel utilize load-bearing structures and also the future tower blocks reinforced concrete flat slab with drop brickwork. This strongly influenced the to be constructed in the south west and panels on a 9.0m column grid. This simple choice of a raft footing due to both total south east corners of the site. Additional low cost system proved successful and and differential settlements being less than exploratory excavations were also carried permitted repeated use of formwork over a for pad footings. The raft construction also out in order to assess the ability to control very large area. had the benefit of creating a watertight the possible water flow during foundation platform early in the programme to allow The 400 bed hotel is entered from the north construction to the development. the start of the slipformed hotel lift and through a porte-cochere directly into the The forward earthworks contract included service core walls. central lobby. The interior area is a construction of a 650m long diaphragm wall cruciform plan, with mini atriums that curve around the perimeter of the site followed by The raft was constructed in two separate around each corner as a group of bulk excavation to foundation level. The 24-hour concrete pours of approximately bedrooms. Each atrium has interconnect• 3 diaphragm walls are 500mm thick and 2500m each, and used a 50/50 blast ing bridges in a spiral arrangement extend from the under side of level 2 car furnace slag/type A cement mix. throughout the 10 storey space. The hotel park at R.L. -1.2 down to toe level, The remainder of the structure, which is also contains a ballroom, full tennis court, a generally at -5.9. to extend through the concrete framed to a maximum level 7, is swimming pool and 10 restaurants. upper sand stratum into clay. The walls founded on profiled pad footings poured were tied with a single line of alluvial The hotel typical floor structures occur integrally with the basement slab. anchors at R.L. 0.00. from levels 7 to 13 inclusive. Two brick Various forms of dewatering were required course (172mm) thick slabs are supported Due to the variability of the soils and water across the site. Generally, dewatering on 150mm thick loadbearing brick walls.

SECTION A-A AT BRIDGES

Bridges at alternate levels

SECTION A-A AT ALTERNATE LEVELS

750 dia column changes to 550 at level six

SECTION B-B 10 2 4 6 8 10m AT LEVEL FIVE ONLY

Fig. 5 Fig. 6 Plan of typical hotel floor levels 7 to 13 Sections at bridges and levels

didn't do anything he would not do expertly, whether it was mathematics, engineering, gardening, climbing or tennis. Things discovered, or rediscovered, by RSJ now look obvious-a mark of true genius! It would not be right to leave a discussion on RSJ's work without some visible reminder that real buildings flowed from his hand. may be somewhat true of his last few years, leading to the hopper. The erection was but in his career generally it would be a done speedily by a few men under an able Unfortunately, as Sir Ove said at our last parody of the true worth of RSJ. He was, ganger with no mechanical plant. Everyone meeting, much of the pre-War, War and first and foremost, a practising engineer in knew it would be right for the job and be post-War work which he and later RSJ were small things and large; he was devoted to trouble-free (barring some event totally associated is left unrecorded, partly detail. John Henderson's tribute to RSJ in outside the terms of reference), since it because it has been lost, and partly the Memorial Issue of The Arup Journal bore the RSJ thumb print. Similarly, any because the 35mm camera and colour film contains the following: contract estimate he made had the same were not such common features then as 'As a small example, his design for the distinctive character, and a site agent was they are today. concrete pump hopper loading gantry at fortunate indeed to have such a document Anyway, from 1946 onwards, the start of Eastbury Park (1942) was a model of as his price guide.' Ove Arup & Partners-RSJ was, of course, engineering economy and grace. It was His drawings on the wartime project a founding partner-some photographic formed from a frame of telegraph poles Heysham Jetty were for long regarded in records of his work are available. supporting some old steel beams from the the firm as a masterpiece of engineering Starting in Dublin where Ove set up an 10 yard, these in turn carrying the roadway detailing and draughtsmanship. Ronald office in 1946 to do some work with Michael Scott, Fig. 1 shows the shell roofs at words and rather full of equations, and Fig. 6 shows a building on the Festival of Donnybrook bus garage. It was during this apparently at a party in Michael Scott's Britain site, probably one of the first The Merlin Hotel, time that another possibly apocryphal story office one night, it was getting very late, prestressed statically indeterminate of Ronald circulates. He had by this time and Michael got the book which Ronald had structures-a diagrid roof which formed Perth, written his book which, as those of you who given him, put it in front of the pianist and the Fairway Restaurant. I shudder to think Western Australia know it will remember, is rather sparse on said 'Now, play that!' of some of the details today, with the Fig. 2 shows what was probably one of the Freyssinet female cones stuck on the Lobby first shell roofs calculated by Ronald. It outside of the concrete, but they worked. Architects: John Andrews Plaza Fig. 1 doesn't give a very good picture of the Fig. 7 shows the hall of Kidbrooke School Donnybrook Bus Garage shells here, but those 3 inch wavy shells do which was at that time the first of the large Keith Pollock (Photo: Deegan-Photo Ltd.) cantilever about 20ft. This is the bus station comprehensive schools built in this at Dublin which stood like that in all its country. It had 2000 students and the roof SECTION A-A Fig. 2 glory for some time while successive Irish of the assembly hall was a concrete shell The Merlin complex comprises a 400 bed Dublin Bus Station governments paid us abandoned work fees dome. The edge beam which you can see on hotel 8,000m2 of office accommodation, a (Photo:copyright Architectural Review) to keep the office alive whilst they made up the right hand side was in this case retail shopping arcade and parking for 1,000 their mind what they wanted to do with it. prestressed. cars in two basement levels with provision Fig. 3 for two later tower blocks. Then we come to perhaps the largest There is rather a nice story about this project because Ronald had finished the The challenge to the structural engineer Brynmawr Rubber Factory exposition of shell concrete in this country; the Brynmawr Works for the Earl of Verulam calculations and then suddenly decided was to find economic solutions to elements Fig. 4 of Enfield Cables, with its nine 90ft. square - something he rarely did - that somebody including the 65m long atrium roof, the ought to check them. And in the first line is 2 domes and a number of cylindrical shells of 60,000m car park and podium deck, the Interior of Brynmawr Factory different types around it. This is shown in the ratio r/R and that he had got wrong. 26m clear span concrete deck for the Everything else was right. So, on being told Fig. 5 Fig. 3. ballroom roof, the interbridge links for the SECTION B-B this, he had a very good lateral thought. He Steel spiral access stair The inside of the dome shells is shown in accommodation levels and the intricate 5 0 5 10 15 20m rang the architect and said he couldn't at Brynmawr Factory vaulted porte-cocheres. Figs. 2-3 Fig. 4. possibly design a shell with the ratio r/R Fig. 6 Ove Arup & Partners were commissioned as Section through building These shells were designed in 1946 before that the architect wanted, it had to be the structural consultants for the John Festival of Britain restaurant roof prestressed concrete really got going in one he had used in his calculations - and Andrews-designed Merlin Hotel Develop• this country, and the edge beams are in no architect could dispute that with ment in March 1981. Fig. 7 reinforced concrete. I think a few years later Ronald! Kidbrooke Comprehensive School The $65m. development is situated on they would certainly have been prestressed. Fig. 8 shows the Printing Works of the Bank assembly hall (Photo: John Maltby) approximately 3.5ha of riverside land at the Fig. 5 is a funny little staircase which went of England. The structure of the main Fig. 8 eastern entrance to Perth City. round two and a half turns and it does that Printing Hall was a series of shells carried Loading dock Bank of England Printing Works The development has been undertaken by STAGE 3 Squash • centre simply because the Earl of Verulam who on arches. The arches were precast and Apartment (Photo: John Holden) Withemsea Pty Ltd., a joint venture was the client had seen one like it in stressed together using the Freyssinet lower Fig. 9 company equally owned by Diamond Hill Switzerland, and please could he have one system, and Fig. 9 shows a diagram of the Prestressing arrangements Pty. Ltd., and Multiplex Constructions Pty. like that. So Ronald said 'Yes, why not?' It prestressing arrangements. Fig. 10 is the for Bank of England Printing Works Ltd., who also constructed the project. was rather slender, and it did move about inside of the construction as it was going The building comprises 3 main elements. Fig. 10 three inches when you walked up it, but in on. There were 22 identical bays; the The hotel, the shops and offices and the car Main production hall later years Ronald went to Switzerland to construction of the first one took three park. of Bank of England Printing Works see this other staircase and found that it weeks and of the last one, two and a half function (Photo: Archie Handford) was anchored at mid-point! days. After a forward siteworks contract, construction proper was commenced in December 1982 and completed some 18 chopping months later in July 1984. It is significant that this short construction time also included complete fit-out of the hotel and Recpl ancillary facilities. i We were involved in all the structural ounce elements of the building. These included the siteworks, foundations, structural frame, precast and brick facades, the atrium roof and external canopies. STAGE 2 Otfice tower The site is adjacent to the Swan River, \ •. is— directly behind a grassed public open Shops space. Natural ground level varied from R.L. 1.70 on the river side (south) of the site to R.L. 4.9 on the north boundary. Water table related almost directly to the Fig. 4 river with some small variation above and Plan of Plaza/Hotel lobby levels below R.L. 1.00. Fig. 11 The structure simply consisted of a number recommendations?" And he said "Yes, Professor Peter Morice Hunstanton Secondary Modern School of columns around the outside and a grid there is a job coming up at the Cement and 'I was just going to go on and say that I (Photo: copyright Architectural Review) structure, two rings, one compression ring Concrete Association for research. Also would like it "recorded" so to speak; that and a tension ring filled in with lightweight there's this book," and he produced people know about the strong connections Fig. 12 roofing. This was taken as far as obtaining Ronald's book. He said "I don't really between Ronald and Yves Guyon because Park Hill housing, Sheffield a tender for the now ridiculous sum of understand this, but I'm sure it is where the Yves, of course, was the great analyst of (Photo: copyright Architectural Review) £193.000, but still it didn't go ahead. future lies, in structural analysis. Read that, France and Ronald was the great analyst of Fig. 13 my boy, and you'll be able to carry on for Britain and they really got on extremely well RAF Hangar, Abingdon years and years and years. It is really the together. They talked the same language, (Photo:copyright John Laing & Sons) This paper was followed by a general basis of your future work." And indeed, he they were extraordinarily good friends, and discussion, and some of the better was quite right. So I read the book: I didn't they both, I think, fed off each other in a Fig. 14 recorded contributions follow. understand it, and it took me many years way and their friendship lasted a very long C&CA, Wexham Springs before I did. I got the job with the C & CA time until the death of both of them....The (Photo: Sydney W. Newbery) Sir Ove Arup: You see, when I met him first at Kiers, I and happily, very soon afterwards, met other thing I would like to record myself, is Fig. 15 could very soon see that his intellect was Ronald and, being involved in concrete the responsibility of Ronald for my now Gaydon Hangars quite unusual, that I hadn't met anybody in research, came across him quite a lot and state of inebriation since he really (Photo: John Laing & Sons) England with what was almost his became, I'm happy to say, very friendly with introduced me to good wines-good wines and opera.' Fig. 16 Continental approach to the problem....He him. Lattice shell at workshop for was very strict. He was a perfectionist. It is On the paper you mentioned, incidentally, I Derek Sugden Scaffolding (GB) Ltd., Mitcham, Surrey quite right that it was very difficult to don't know whether it is possible - perhaps 'I'd like to illustrate one or two facets of understand what he had written....He said John (Henderson) can help here-but I Ronald's character. "I'm nottrying to make it easier for people". understand that the paper was submitted to Ronald asked me at my interview what I He was trying to get the admiration of the the Institution of Civil Engineers and knew about matrices and I vaguely people who understood him you see. He Pippard was one of the assessors and said wondered what mattresses had to do with was writing for his kind of people and he this was nonsense and far too difficult, and structural engineering! But I managed didn't suffer fools gladly. Now that can both nobody would be able to read this sort of somehow to get over that, and we went on be good and bad....but he was also practical thing, so the paper was left, and I still to talk about real things like music. at the same time....' possess a copy of it.' Although I never moved in the rarified air of Professor Peter Morice: John Henderson the analyst which surrounded Ronald, I was 'I feel I have an enormous debt to Jenkins. 'It was partly my fault that it wasn't involved with him on one or two jobs. On The first time I ever came across him was published. What Pippard said was that Corsets Silhouette where we were soon after I'd come out of College. I was people won't understand it. He didn't say it rebuilding some H.P. shells designed by bored with what I was doing at Surrey was nonsense. He said that if you aided and others, I received one of the most valuable County Council so I went back to see my abetted to make it easier to understand lessons of my professional life. When professor who was Sir Alfred Pugsley in then he would publish it....but Jenkins said rushing in to his office to tell him that he Bristol and said "I don't like what I'm doing, "I don't want it messed about with", which must answer "this important letter" can you find me a better job? Any of course was quite right. immediately, he advised me to put it aside for a week. The lesson went on-"Put it aside for another week", he added, "then you will discover that in 99 cases out of 100 there is no need to do anything." I soon discovered that this 'Kutusov' approach was very successful, and it became an important part of my own life style. He was the first man I met in Arups who was actually listening to Britten's operas in the '50s. He really was a man of many parts.., especially wine...and Dry Martinis. I was really a Gin man until I met Ronald and he introduced me to the delights of Dry Martinis.

Several other people contributed to the * discussion including Mrs. Betty Jenkins, t who described Ronald making a paper model of the Brynmawr staircase on the kitchen table. V Figs. 17-19 Competition entry by Alison & Peter Smithson 17 Ul for the rebuilding of Coventry Cathedral Fig. 11 is a view of Hunstanton School. It a couple of Royal Air Force hangars by fabricating lattices of tubular steelwork, was a very simple building but the sections entirely different methods. Fig. 13 shows putting them up in position and then which the Smithsons had chosen to put in the one at Abingdon, made entirely of shell covering them with lightweight concrete. their competition design were without the roofs. They were cast on the ground and Fig. 16 shows one of these shells. benefit of engineers, and it took us a long jacked 40ft. up into the air. Whilst the edge Now I come to a project which was not time and a considerable appeal to plastic beams were on the ground the shells stayed built. The Smithson's competition design collapse theory to convince ourselves that up quite happily as arches, so enabling for Coventry Cathedral was one of the with the benefit of engineers we could leave them to be cast with a travelling shutter. projects which Ronald would have most them as they were. Fig. 14 shows a small project at Wexham liked to have built. Ronald occasionally, and very occasionally, Springs when Professor Morice of got mixed up with what the rest of us Southampton University, another close The Coventry Cathedral design was a 200ft. engineers would call bread and butter work, friend of Ronald's, was director there. An square shell carried on edge beams, and and Fig. 12 shows the Park Hill Flats at interesting thing about this job was that for Figs. 17, 18 and 19 show the proposal and Sheffield. The reason why he did is beyond a long time the shells had no waterproofing its relationship to the existing spire which me now, but apparently there were site on them at all - the valleys which were the was all that was left after the bombing of meetings he went to for several months and 'edge beams' were prestressed. Coventry. didn't say a thing. One day he was noted to Very occasionally, Jack Zunz or I got Another unbuilt project was a new roof for be about to speak and everybody waited Ronald to build a statically determined the Centre Court at Wimbledon. This would with bated breath. And these words came: 'I structure. He wasn't very keen on such have had the same outline as the well- believe that is my pencil you have'. structures, but Fig. 15 shows the Gaydon known court today, but all the internal During these years when he formed a very Hangars-a roof with a three-pinned arch. columns would have moved. (We had a *3M close relationship with B.H. Broadbent, Another development he was concerned special sort of rain which moved uphill to 19 12 then a director of John Laing, we designed with was a lattice shell-a device for pre• get away from the drainage problems.) Fig. 11 The structure simply consisted of a number recommendations?" And he said "Yes, Professor Peter Morice Hunstanton Secondary Modern School of columns around the outside and a grid there is a job coming up at the Cement and 'I was just going to go on and say that I (Photo: copyright Architectural Review) structure, two rings, one compression ring Concrete Association for research. Also would like it "recorded" so to speak; that and a tension ring filled in with lightweight there's this book," and he produced people know about the strong connections Fig. 12 roofing. This was taken as far as obtaining Ronald's book. He said "I don't really between Ronald and Yves Guyon because Park Hill housing, Sheffield a tender for the now ridiculous sum of understand this, but I'm sure it is where the Yves, of course, was the great analyst of (Photo: copyright Architectural Review) £193.000, but still it didn't go ahead. future lies, in structural analysis. Read that, France and Ronald was the great analyst of Fig. 13 my boy, and you'll be able to carry on for Britain and they really got on extremely well RAF Hangar, Abingdon years and years and years. It is really the together. They talked the same language, (Photo:copyright John Laing & Sons) This paper was followed by a general basis of your future work." And indeed, he they were extraordinarily good friends, and discussion, and some of the better was quite right. So I read the book: I didn't they both, I think, fed off each other in a Fig. 14 recorded contributions follow. understand it, and it took me many years way and their friendship lasted a very long C&CA, Wexham Springs before I did. I got the job with the C & CA time until the death of both of them....The (Photo: Sydney W. Newbery) Sir Ove Arup: You see, when I met him first at Kiers, I and happily, very soon afterwards, met other thing I would like to record myself, is Fig. 15 could very soon see that his intellect was Ronald and, being involved in concrete the responsibility of Ronald for my now Gaydon Hangars quite unusual, that I hadn't met anybody in research, came across him quite a lot and state of inebriation since he really (Photo: John Laing & Sons) England with what was almost his became, I'm happy to say, very friendly with introduced me to good wines-good wines and opera.' Fig. 16 Continental approach to the problem....He him. Lattice shell at workshop for was very strict. He was a perfectionist. It is On the paper you mentioned, incidentally, I Derek Sugden Scaffolding (GB) Ltd., Mitcham, Surrey quite right that it was very difficult to don't know whether it is possible - perhaps 'I'd like to illustrate one or two facets of understand what he had written....He said John (Henderson) can help here-but I Ronald's character. "I'm nottrying to make it easier for people". understand that the paper was submitted to Ronald asked me at my interview what I He was trying to get the admiration of the the Institution of Civil Engineers and knew about matrices and I vaguely people who understood him you see. He Pippard was one of the assessors and said wondered what mattresses had to do with was writing for his kind of people and he this was nonsense and far too difficult, and structural engineering! But I managed didn't suffer fools gladly. Now that can both nobody would be able to read this sort of somehow to get over that, and we went on be good and bad....but he was also practical thing, so the paper was left, and I still to talk about real things like music. at the same time....' possess a copy of it.' Although I never moved in the rarified air of Professor Peter Morice: John Henderson the analyst which surrounded Ronald, I was 'I feel I have an enormous debt to Jenkins. 'It was partly my fault that it wasn't involved with him on one or two jobs. On The first time I ever came across him was published. What Pippard said was that Corsets Silhouette where we were soon after I'd come out of College. I was people won't understand it. He didn't say it rebuilding some H.P. shells designed by bored with what I was doing at Surrey was nonsense. He said that if you aided and others, I received one of the most valuable County Council so I went back to see my abetted to make it easier to understand lessons of my professional life. When professor who was Sir Alfred Pugsley in then he would publish it....but Jenkins said rushing in to his office to tell him that he Bristol and said "I don't like what I'm doing, "I don't want it messed about with", which must answer "this important letter" can you find me a better job? Any of course was quite right. immediately, he advised me to put it aside for a week. The lesson went on-"Put it aside for another week", he added, "then you will discover that in 99 cases out of 100 there is no need to do anything." I soon discovered that this 'Kutusov' approach was very successful, and it became an important part of my own life style. He was the first man I met in Arups who was actually listening to Britten's operas in the '50s. He really was a man of many parts.., especially wine...and Dry Martinis. I was really a Gin man until I met Ronald and he introduced me to the delights of Dry Martinis.

Several other people contributed to the * discussion including Mrs. Betty Jenkins, t who described Ronald making a paper model of the Brynmawr staircase on the kitchen table. V Figs. 17-19 Competition entry by Alison & Peter Smithson 17 Ul for the rebuilding of Coventry Cathedral Fig. 11 is a view of Hunstanton School. It a couple of Royal Air Force hangars by fabricating lattices of tubular steelwork, was a very simple building but the sections entirely different methods. Fig. 13 shows putting them up in position and then which the Smithsons had chosen to put in the one at Abingdon, made entirely of shell covering them with lightweight concrete. their competition design were without the roofs. They were cast on the ground and Fig. 16 shows one of these shells. benefit of engineers, and it took us a long jacked 40ft. up into the air. Whilst the edge Now I come to a project which was not time and a considerable appeal to plastic beams were on the ground the shells stayed built. The Smithson's competition design collapse theory to convince ourselves that up quite happily as arches, so enabling for Coventry Cathedral was one of the with the benefit of engineers we could leave them to be cast with a travelling shutter. projects which Ronald would have most them as they were. Fig. 14 shows a small project at Wexham liked to have built. Ronald occasionally, and very occasionally, Springs when Professor Morice of got mixed up with what the rest of us Southampton University, another close The Coventry Cathedral design was a 200ft. engineers would call bread and butter work, friend of Ronald's, was director there. An square shell carried on edge beams, and and Fig. 12 shows the Park Hill Flats at interesting thing about this job was that for Figs. 17, 18 and 19 show the proposal and Sheffield. The reason why he did is beyond a long time the shells had no waterproofing its relationship to the existing spire which me now, but apparently there were site on them at all - the valleys which were the was all that was left after the bombing of meetings he went to for several months and 'edge beams' were prestressed. Coventry. didn't say a thing. One day he was noted to Very occasionally, Jack Zunz or I got Another unbuilt project was a new roof for be about to speak and everybody waited Ronald to build a statically determined the Centre Court at Wimbledon. This would with bated breath. And these words came: 'I structure. He wasn't very keen on such have had the same outline as the well- believe that is my pencil you have'. structures, but Fig. 15 shows the Gaydon known court today, but all the internal During these years when he formed a very Hangars-a roof with a three-pinned arch. columns would have moved. (We had a *3M close relationship with B.H. Broadbent, Another development he was concerned special sort of rain which moved uphill to 19 12 then a director of John Laing, we designed with was a lattice shell-a device for pre• get away from the drainage problems.) Scott, Fig. 1 shows the shell roofs at words and rather full of equations, and Fig. 6 shows a building on the Festival of Donnybrook bus garage. It was during this apparently at a party in Michael Scott's Britain site, probably one of the first The Merlin Hotel, time that another possibly apocryphal story office one night, it was getting very late, prestressed statically indeterminate of Ronald circulates. He had by this time and Michael got the book which Ronald had structures-a diagrid roof which formed Perth, written his book which, as those of you who given him, put it in front of the pianist and the Fairway Restaurant. I shudder to think Western Australia know it will remember, is rather sparse on said 'Now, play that!' of some of the details today, with the Fig. 2 shows what was probably one of the Freyssinet female cones stuck on the Lobby first shell roofs calculated by Ronald. It outside of the concrete, but they worked. Architects: John Andrews Plaza Fig. 1 doesn't give a very good picture of the Fig. 7 shows the hall of Kidbrooke School Donnybrook Bus Garage shells here, but those 3 inch wavy shells do which was at that time the first of the large Keith Pollock (Photo: Deegan-Photo Ltd.) cantilever about 20ft. This is the bus station comprehensive schools built in this at Dublin which stood like that in all its country. It had 2000 students and the roof SECTION A-A Fig. 2 glory for some time while successive Irish of the assembly hall was a concrete shell The Merlin complex comprises a 400 bed Dublin Bus Station governments paid us abandoned work fees dome. The edge beam which you can see on hotel 8,000m2 of office accommodation, a (Photo:copyright Architectural Review) to keep the office alive whilst they made up the right hand side was in this case retail shopping arcade and parking for 1,000 their mind what they wanted to do with it. prestressed. cars in two basement levels with provision Fig. 3 for two later tower blocks. Then we come to perhaps the largest There is rather a nice story about this project because Ronald had finished the The challenge to the structural engineer Brynmawr Rubber Factory exposition of shell concrete in this country; the Brynmawr Works for the Earl of Verulam calculations and then suddenly decided was to find economic solutions to elements Fig. 4 of Enfield Cables, with its nine 90ft. square - something he rarely did - that somebody including the 65m long atrium roof, the ought to check them. And in the first line is 2 domes and a number of cylindrical shells of 60,000m car park and podium deck, the Interior of Brynmawr Factory different types around it. This is shown in the ratio r/R and that he had got wrong. 26m clear span concrete deck for the Everything else was right. So, on being told Fig. 5 Fig. 3. ballroom roof, the interbridge links for the SECTION B-B this, he had a very good lateral thought. He Steel spiral access stair The inside of the dome shells is shown in accommodation levels and the intricate 5 0 5 10 15 20m rang the architect and said he couldn't at Brynmawr Factory vaulted porte-cocheres. Figs. 2-3 Fig. 4. possibly design a shell with the ratio r/R Fig. 6 Ove Arup & Partners were commissioned as Section through building These shells were designed in 1946 before that the architect wanted, it had to be the structural consultants for the John Festival of Britain restaurant roof prestressed concrete really got going in one he had used in his calculations - and Andrews-designed Merlin Hotel Develop• this country, and the edge beams are in no architect could dispute that with ment in March 1981. Fig. 7 reinforced concrete. I think a few years later Ronald! Kidbrooke Comprehensive School The $65m. development is situated on they would certainly have been prestressed. Fig. 8 shows the Printing Works of the Bank assembly hall (Photo: John Maltby) approximately 3.5ha of riverside land at the Fig. 5 is a funny little staircase which went of England. The structure of the main Fig. 8 eastern entrance to Perth City. round two and a half turns and it does that Printing Hall was a series of shells carried Loading dock Bank of England Printing Works The development has been undertaken by STAGE 3 Squash • centre simply because the Earl of Verulam who on arches. The arches were precast and Apartment (Photo: John Holden) Withemsea Pty Ltd., a joint venture was the client had seen one like it in stressed together using the Freyssinet lower Fig. 9 company equally owned by Diamond Hill Switzerland, and please could he have one system, and Fig. 9 shows a diagram of the Prestressing arrangements Pty. Ltd., and Multiplex Constructions Pty. like that. So Ronald said 'Yes, why not?' It prestressing arrangements. Fig. 10 is the for Bank of England Printing Works Ltd., who also constructed the project. was rather slender, and it did move about inside of the construction as it was going The building comprises 3 main elements. Fig. 10 three inches when you walked up it, but in on. There were 22 identical bays; the The hotel, the shops and offices and the car Main production hall later years Ronald went to Switzerland to construction of the first one took three park. of Bank of England Printing Works see this other staircase and found that it weeks and of the last one, two and a half function (Photo: Archie Handford) was anchored at mid-point! days. After a forward siteworks contract, construction proper was commenced in December 1982 and completed some 18 chopping months later in July 1984. It is significant that this short construction time also included complete fit-out of the hotel and Recpl ancillary facilities. i We were involved in all the structural ounce elements of the building. These included the siteworks, foundations, structural frame, precast and brick facades, the atrium roof and external canopies. STAGE 2 Otfice tower The site is adjacent to the Swan River, \ •. is— directly behind a grassed public open Shops space. Natural ground level varied from R.L. 1.70 on the river side (south) of the site to R.L. 4.9 on the north boundary. Water table related almost directly to the Fig. 4 river with some small variation above and Plan of Plaza/Hotel lobby levels below R.L. 1.00. Parking for 1,000 cars is accommodated table level encountered during the spears were used in the north sandy strata over two basement levels covering the total geotechnical investigation, foundations and sumps, wellpoints and drains in the area of the site. The lower basement, were selected along with recommendations clay to the south. The slabs interconnecting accessed through the car park by ramps of improvement procedures where the pad footings were designed for uplift from the southern entry, is at R.L.-1.70 unsatisfactory ground may be encountered. pressures which were controlled by the with an upper basement level at R.L. 1.30. The 13 storey hotel tower to the north of the inclusion of a grid of pressure relief tubes Site investigations were carried out to site is founded on a 1.5m thick raft with a cast into the basement. enable assessment of suitable foundation ground bearing pressure of 150 kPa. The systems for the hotel tower, the podium The car parking floor structure is a upper levels of the hotel utilize load-bearing structures and also the future tower blocks reinforced concrete flat slab with drop brickwork. This strongly influenced the to be constructed in the south west and panels on a 9.0m column grid. This simple choice of a raft footing due to both total south east corners of the site. Additional low cost system proved successful and and differential settlements being less than exploratory excavations were also carried permitted repeated use of formwork over a for pad footings. The raft construction also out in order to assess the ability to control very large area. had the benefit of creating a watertight the possible water flow during foundation platform early in the programme to allow The 400 bed hotel is entered from the north construction to the development. the start of the slipformed hotel lift and through a porte-cochere directly into the The forward earthworks contract included service core walls. central lobby. The interior area is a construction of a 650m long diaphragm wall cruciform plan, with mini atriums that curve around the perimeter of the site followed by The raft was constructed in two separate around each corner as a group of bulk excavation to foundation level. The 24-hour concrete pours of approximately bedrooms. Each atrium has interconnect• 3 diaphragm walls are 500mm thick and 2500m each, and used a 50/50 blast ing bridges in a spiral arrangement extend from the under side of level 2 car furnace slag/type A cement mix. throughout the 10 storey space. The hotel park at R.L. -1.2 down to toe level, The remainder of the structure, which is also contains a ballroom, full tennis court, a generally at -5.9. to extend through the concrete framed to a maximum level 7, is swimming pool and 10 restaurants. upper sand stratum into clay. The walls founded on profiled pad footings poured were tied with a single line of alluvial The hotel typical floor structures occur integrally with the basement slab. anchors at R.L. 0.00. from levels 7 to 13 inclusive. Two brick Various forms of dewatering were required course (172mm) thick slabs are supported Due to the variability of the soils and water across the site. Generally, dewatering on 150mm thick loadbearing brick walls.

SECTION A-A AT BRIDGES

Bridges at alternate levels

SECTION A-A AT ALTERNATE LEVELS

750 dia column changes to 550 at level six

SECTION B-B 10 2 4 6 8 10m AT LEVEL FIVE ONLY

Fig. 5 Fig. 6 Plan of typical hotel floor levels 7 to 13 Sections at bridges and levels

didn't do anything he would not do expertly, whether it was mathematics, engineering, gardening, climbing or tennis. Things discovered, or rediscovered, by RSJ now look obvious-a mark of true genius! It would not be right to leave a discussion on RSJ's work without some visible reminder that real buildings flowed from his hand. may be somewhat true of his last few years, leading to the hopper. The erection was but in his career generally it would be a done speedily by a few men under an able Unfortunately, as Sir Ove said at our last parody of the true worth of RSJ. He was, ganger with no mechanical plant. Everyone meeting, much of the pre-War, War and first and foremost, a practising engineer in knew it would be right for the job and be post-War work which he and later RSJ were small things and large; he was devoted to trouble-free (barring some event totally associated is left unrecorded, partly detail. John Henderson's tribute to RSJ in outside the terms of reference), since it because it has been lost, and partly the Memorial Issue of The Arup Journal bore the RSJ thumb print. Similarly, any because the 35mm camera and colour film contains the following: contract estimate he made had the same were not such common features then as 'As a small example, his design for the distinctive character, and a site agent was they are today. concrete pump hopper loading gantry at fortunate indeed to have such a document Anyway, from 1946 onwards, the start of Eastbury Park (1942) was a model of as his price guide.' Ove Arup & Partners-RSJ was, of course, engineering economy and grace. It was His drawings on the wartime project a founding partner-some photographic formed from a frame of telegraph poles Heysham Jetty were for long regarded in records of his work are available. supporting some old steel beams from the the firm as a masterpiece of engineering Starting in Dublin where Ove set up an 10 yard, these in turn carrying the roadway detailing and draughtsmanship. Ronald office in 1946 to do some work with Michael The brickwork has a design compressive strength of 50 MPa maximum, varying to 30 Two papers late in his life and published in MPa at the lower floors. The tops of the Ronald Stewart Jenkins: the Memorial Issue of The Arup Journal brick walls have slip joints with neoprene deal with such subjects: Towards a sliding bearings at the underside of the engineer and mathematician Variational Method for the Static concrete roof level to accommodate Equilibrium of Curved Bodies and Shells differential movement. The lift, stairs and and Membrane Theory in General Co• service cores at the intersection of each of Ronald Hobbs the four hotel wings are 200mm thick ordinates by Matrix-Tensor Methods. I am not aware that this work has led slipformed concrete. These walls take the This talk was given to the History Study Group of the anywhere - perhaps the computer which majority of the lateral design forces for the Institution of Structural Engineers at Imperial College on 16 December 1982. building. does not admire elegance has made them unnecessary - but I am sure that if Ronald The level 6 hotel accommodation level is a Introduction undoubted elegance. Ronald attacked most had been able to develop them, our 1.5m thick beam and slab structure Perhaps the best example I can give of problems as elegantly as possible; in understanding of complex three- transferring the hotel typical loadbearing Ronald's approach to his subject is the day solving a statically indeterminate dimensional shell structures, thick or thin, brickwork to the 9.0m column grid of the he came to the office with his completely framework he would spend much time in would have been greatly increased. basement carpark. The services from upper general definition of n-dimensional strain. choosing the necessary cuts and releases Ronald, of course, was not one of this level bedrooms pass down to the underside Most engineers, for obvious reasons, begin in order to make the resulting equations as world's natural, easy, communicators. of level 6 slab and then travel laterally by making a maximum number of well-conditioned as possible. through the beam structure to exit ducts. approximations or assumptions; Ronald All this is perhaps summed up in a well- Anyone reading-if 'reading' is the right always preferred to approach problems as loved and much polished summary in word - Cylindrical Shell Structures can see Atrium generally as possible and build in the Chapter 8 of The Theory and Design of that, but by the time you understood him The atrium roof is constructed of a series of necessary assumptions which flow from Cylindrical Shell Structures: and what he was driving at, it stuck for ever. steel transparent Lexan -clad arches, real life as late as possible. meeting in the centre of the hotel at a 'When matrices are used we obtain the You would also appreciate the This was the mathematician showing square gridded space frame. All the symmetric form as a geometrical con• mathematical elegance of all his work. through. steelwork uses standard tube or rolled sequence, without appeal to the concept One example is an equation in the book on sections and welded and bolted I should also like to quote from Ove Arup's ion of work, which is merely the name of cylindrical shell structures. In one line a connections. The hotel roof, the front introduction to RSJ's book The Theory and a scalar invariant associated with contra- multiplier in a matrix equation is given as entrance canopy and the rear podium Design of Cylindrical Shell Structures: gredient sets'. L= A little later the same equation canopy are of similar construction. The 'It would, however, not be advisable-or I am sure that today's very young students larger rear canopy is a 60m long x 20m wide even safe-to employ approximate of 'New Mathematics' would appreciate 2 ST triple-vaulted tubular-framed structure. The methods in all cases. They ought to be that. begins ^^ • On being asked by one subcontract for the steelwork to these roofs employed only by designers experienced in One of the tests of Ronald's concepts came was approximately $1.5m. the application of the complete theory.' immediately after the War with the eminent engineer to explain, Ronald was Ballroom roof Ronald, however, was essentially an introduction of prestressing to statically puzzled; he was, after all, only solving a set The ballroom roof forms the external deck engineer, and his meticulous attention to indeterminate structures. The calculation of differential equations, and reversing that to the 20m long swimming pool. The roof engineering detail-where the reinforcing of the so-called parasitic stresses was particular multiplier merely changed the spans 26m across an octagonal 6m high bars actually went in the concrete-was a taken in its stride by this concept. It also value of the arbitrary constants. So why the space with a grillage of beams and slab. by-word to the few people who had worked naturally dealt with forces created by question? The beams to the ballroom roof are closely with him. temperature and shrinkage. Jenkins the man perforated for a depth of 500mm below slab I first met RSJ in late 1948-a client had Nowadays we all, or almost all, use Ronald as a man was difficult to know at level, in one direction, to accommodate recommended to Ove that he take me on, computers, large or little, for all first, essentially shy, which was sometimes services. A 2-stage in situ beamlBondek and I suppose he felt that if I saw all the calculations. When I first met Ronald he mistaken as aloofness. slab construction method was devised to partners one would come up with a good was using a hand-operated Facit for the An example of this, and one of my favourite allow the ductwork to be fixed from the reason why they shouldn't. Anyway, I solution of 8 x 8 and larger simultaneous memories of Ronald, is the time two now upper level prior to pouring the slab. The joined, and after a couple of months, equations, using Fox's method for inverting eminent services engineers came to visit design also included provision of two started work with Ronald on various a matrix. Computers chew up equations him. I found them wandering around and adjustable universal column temporary buildings in the Festival of Britain. and spit out the answers without tasting sat them in his office to wait. I went away to them at all-but maybe that's just props to allow delaying infill of the 4.5m Statically indeterminate structures do some work, came back an hour later: nostalgia for the heady post-War years. square crane opening which also existed At that time my knowledge of the solution they were still there, no sign of Ronald, so I He was, however, at a very early time through the ballroom area. of statically indeterminate structures said 'Well, what happened?' The facade of the hotel is a combination of rested on a confusion of Hardy Cross and acutely aware of what computers could do 'Well', said the visitors, 'he came in, sat at face brick and precast concrete spandrel strain energy. for us. His contribution to the 'Dome of his desk and he started doing some work.' units. The precast units vary in thickness Discovery' paper at the Civils in 1952 Ronald very quickly introduced me to Now, it was nearly impossible to interrupt from 100mm to 180mm and were made on brought from one of the authors a matrices, via Aitken's little book and his Ronald when he was actually doing some site in steel forms set up on the podium question - What are digital computers?- own adaptation of influence coefficients calculations. 'And,' they said 'a little later slab at level 3. Temporary shelf angles held but it must be remembered that it wasn't using matrices. He managed to condense he got up, and he put on his coat and he the spandrels in position and allowed until one year later that IBM entered the the whole subject of statically went out.' I asked him the next morning, adjustment until an in situ concrete stitch computer field! Computers have taken the indeterminate structures to three very short drudgery from arithmetic calculations, but and he said 'Oh dear. I'd forgotten. I was poured for final support. lines-that is my memory: John Henderson also possibly have taken some of the joy thought they were the auditors!' We had a The hotel is linked by stairs and escalators says half a page! This, padded out a bit, and pleasure from analysis. I also think that habit in those days of lending out his office to a series of external courtyards, plazas was given as a paper to the Euler Society in it was a great pity that RSJ became to the auditors once a year so they could and arcades which are located at level 3. 1953, after being refused by the Institution seriously ill before computers had caught check whether we were making a profit or The structural slab form of the car park of Civil Engineers as being either (a) too up with him! not. below this level is repeated for these areas, easy, or (b) too complex. The complete However, through his work he formed with adjustment to support extensive paper is, I believe, only published in the Shell structures several unusual and lasting friendships. For landscaping, planting and precast paving. Ronald Jenkins Memorial Issue oiThe Arup The other great interest in Ronald's example, with the contractor engineer, the The plaza slabs were constructed in a Journal. late B.H. Broadbent, and the architect Peter sequence incorporating control strips professional life was the 'third dimension'. It had long been clear that Ronald had Many engineers and unfortunately quite a Smithson - two entirely different people between expansion joints at 60m centres to considerable ability, but it was not until fire- few architects are two-dimensional men, but who both intuitively understood that allow for concrete shrinkage and thermal watching during the War that he ran into and it is a mark of the great engineer or Ronald's appreciation of the part structures movements. matrices and realized what a powerful tool architect, his understanding and use of the play in buildings went far deeper than The shopping arcade has 40 retail they could be, coupled with Ostenfeldt's third dimension. To me at least, Ronald's merely his mathematical ability to solve tenancies to serve both hotel patrons and influence coefficients, to which, in the understanding of the third dimension was complex problems. To me, nowhere was general public. Additionally, the centre original Danish, he had been introduced by virtually complete and quite intuitive. this more demonstrated than in incorporates a health club, squash courts, Ove Arup some time before-they were Outwardly, this is perhaps best shown in Hunstanton School, a simple project-as and a service station at the entrance to the both working for J.L. Kier at the time. his interest in, and work on, shell simple as the Smithsons could afford to car park. John Henderson will no doubt remind us structures. make it-but where in the course of its solution Jack Zunz and I learned virtually Offices graphically how he just happened to By the time I met him, RSJ had already everything there was to know about the The offices from level 4 to level 7 wrap introduce matrices to Ronald Jenkins one published Cylindrical Shell Structures and plastic theory at that date-and still the around the plaza areas on three sides of the night; an introduction which I feel sure that was well on the way to an enduring and building stands up! project. The 9.0m diagonal column grid John will agree has been amply repaid, not increasing interest in the mathematics of extends through from the car park and to mention the teaching of later engineering; towards the end of his career Looking back over 35 years, and certainly supports the flat plate concrete floor slab generations of Imperial College students. this was taking him into esoteric and on reading RSJ's published works, one and roof structure. The columns are set The whole concept of statically in• rarefied atmospheres where few could might be excused for thinking that here was back from the facades giving mullion-free determinate structures set out by Jenkins follow-I, for one, was only happy at a theoretical engineer bemused by glazing and 12m open plan office spaces. had an immediate appeal because of its ground level. mathematics for mathematics' sake. This Costs The building provided a gross area of 9,500m2 of which 8,250m2 was office space completed to good quality property developers, standards with raised floors and carpet throughout. The total cost of the building was £7m. for which we were directly commissioned by Leslie & Godwin. An additional £2.5m. was spent on fitting up the interior. This included the fitting up of the restaurant, kitchen, bar, computer room and offices as well as a complete range of new furniture for the whole building. Start on site was delayed by two months but apart from this, the building was completed to programme and was within r the budget. \

Reflections in the bronze glass outer skin and below: the main office entrance

Programme

Arup Associates commissioned by Leslie & Godwin September 1978

Outline Proposals approved by Leslie & Godwin December 1978

Outline Planning Permission January 1980

Imperial Group Pension Trust Ltd. became client March 1980

Revised scheme design approved by Imperial June 1980

Detailed planning permission November 1980 Access to the offices is through possible, and went from the start for 'fast octagonally-shaped load-bearing brick stair tracking' with design proceeding in parallel Laing Management Contracting Ltd. cores located around the site. The stairs to with construction. We made extensive use appointed these cores, and the hotel fire escapes, are of our in-house computer and suite of June 1981 constructed of prefabricated steel with an OASYS structural computer programs to Start on site upturned 'U' shaped tread. The steel stairs assist in producing the documents ahead November 1981 were installed early in the programme to of programme. allow temporary access; later the treads Now completed, the development has Building hand-over were filled with concrete to provide a per• already established an identity in Perth and February 1983 manent (less noisy) final product. is proving popular with both hotel patrons Multiplex required the building as soon as Interior design and and general public alike. fitting out contract completed Credits August 1983 Architects: John Andrews International Pty. Credits Client: Client: Withernsea Pty. Ltd. Imperial Group Pension Trust Ltd. Main contractors: Multiplex Contractors Pty. Ltd. Designed by: Quantity surveyors: Arup Associates Rider Hunt and Partners Main contractor: Services consultants: Laing Management Contracting Ltd. Matthew Hall Pty. Ltd. PAiofos: Photos: Peter Cook Harry Sowden Crispin Boyle Arup Associates constructed in four phases. The phases areas of very limited headroom and City site: were to be overlapped as far as was restricted access. Lovat Lane practical, allowing for the extremely The new buildings were all designed to confined sites, their relative positions and maximize available lettable area on infill the lack of access. Two buildings were Architects: sites. The client required all new constructed in each of Phases 1 & 2 (D&Q The Thomas Saunders Partnership construction to be tight to the adjoining followed by R&S), with Building AB buildings and internal columns to be used constructed under Phase 3 and M under only if essential. With one exception the Deborah Lazarus Phase 4, buildings have six storeys including a Geology and site conditions single basement and they range in size A site investigation comprising four from approximately 440- 1720m2. We Introduction boreholes was commissioned in 1974. The adopted a basic scheme for the Phase 1 The Lovat Lane Conservation Area covers information obtained was supplemented by buildings and used this, with modifications the group of narrow streets to the west of two additional investigations, each where necessary, on the subsequent the Monument, due north of Billingsgate. comprising a borehole and various trial phases. A reinforced concrete framed This is the area which until about 10 years pits, in 1981 and 1982. structure with coffered, two-way spanning ago housed the fish merchants'offices and The geological succession is generally fill slabs was used, with lateral stability stores in buildings dating back generally to overlying gravel above the London Clay. provided by reinforced concrete walls to the the latter part of the 19th century. The Varying conditions are encountered, cores. In general the cores were located, at history of the area goes back a good deal however, due to the slope of the area least after consultation, to assist with further, with medieval remains uncovered towards the river. In particular the site at keeping spans to a size consistent with the attributable to the town house of the the bottom of Lovat Lane differs somewhat depth of slab selected without the need for abbotts of Waltham. A fine Wren church in from those further up. The properties of the internal columns; in one instance only, St. Mary at Hill dates back to 1670 and is clay are slightly different and persistent Building AB, this was not achieved; To held to be one of the most interesting bands of claystone were encountered maximize the coffered areas of slab in the among those remaining. irregularly shaped buildings, a 600mm during piling. In the early 1970s we were appointed by waffle was chosen rather than the more Structural schemes Compass Securities with the Thomas common 900mm module. Storey heights Saunders Partnership as architect to advise A variety of construction materials was were selected to suit the existing buildings on the development of the area for offices. encountered and indeed used during the and the slope of the lanes and the slab The brief initial phase of refurbishment. The majority depth then tended to be determined by the of the floors were timber while vertical required clear height and depth of false The original intention was to demolish most elements were steelwork or load-bearing ceiling to suit air-conditioning ductwork. of the existing buildings and to construct brickwork. Where loads were increased or one 'mega block' which would bridge new elements of vertical structure The layout of the buildings was not felt to across Lovat Lane, from Botolph Lane in introduced, new foundations were required be suitable for a raft foundation and the west to St. Mary at Hill in the east (see and underpinning of existing wall footings shallow pad footings would have been Fig. 2) This was rejected, perhaps not was necessary where basement depths uneconomically large due to the surprisingly, by the City planners, and our were increased. Bored piles were installed eccentricity imposed by keeping all vertical work at this time consisted essentially of loads at the perimeter of the building, and major refurbishment of individual units. in several instances, generally working in Schemes were complicated by the Fig. 1 requirement both to retain several listed Building 'R': facades, and to avoid the payment of part elevation: Development Land Tax in virtually all cases. (Drawn by This latter restriction related in part to the Colin Barnard) proportion of new floor area which was permitted; where existing floors were retained in consequence, the available headroom was often low and did not allow the introduction of significant service zones. Work effectively ceased in 1978 with a number of buildings remaining vacant and semi-derelict. In 1981 the development had been taken over by Guardian Royal Exchange Assurance and the concept had changed to that of the 'City Village'. The brief was to redevelop the derelict buildings as small, high quality offices and the planning consent was based on a series of ornate and complex elevations which would re-create original features from the surrounding area. Fig. 2 Six new buildings were required, to be Site plan

New construction Refurbishment

Botolph Lane mm

Lovat Lane Son Rut; i Qui P 4

SI Ma,, al

18 Ackermann electrical floor outlet , open the cooling system. This heat is later Electrical services rejected back into the space as the The continuous air handling luminaires Fig. 3 temperature tails at night and in the early located between the ceiling ribs in office morning. The computer program predicted areas were specially designed for the View up Lovat Lane that a constant supply air temperature of building and developed with Thorn EMI. Fig. 4 18.5°C with a constant supply air volume of They provide an average 600 lux at working six changes in the worst zone would plane and also evenly light the whole of the Building 'D' maintain a maximum dry resultant ribbed soffit. Fig. 5 temperature of 22°C at 1.5m above floor The luminaires have continuous fluor• Building 'AB' with terracotta facade level. A maximum temperature in the return escent tubes with white cross blade louvres and 'onion' dome air duct of 28°C was anticipated. below a continuous extract duct which is Fig. 6 Subsequent monitoring of the building's triangular in section. On both side faces of Stonemason at work on plaque, drawing environment has proved the accuracy of the duct are finely perforated metal panels attention to weathervane on Building 'AB' these predictions and confirmed that no with absorbent acoustic backing to limit j room terminal controls are required to cater the amount of sound which is reflected for the repositioning of the outlets to of the original after a protracted battle with back into the office space. The amount of provide a new load pattern. A sophisticated the planners to demolish the latter, which air extracted from the space can be varied control system is. however, provided to the was in extremely poor condition and which along the full length of the duct by opening central air handling plant to utilize outside we concluded was unstable: this was the or closing regularly spaced outlets. air and evaporative cooling whenever so-called 'Terracotta Facade' and the new Segregated mains with through wiring possible. wall is also partly faced with terracotta facilities are provided as well as 300mm/8W blocks, copied from the originals, which are emergency lamps, inverters and control The air handling plant for the offices is particularly attractive. gear fed from a central battery. The located at roof level and is divided into four Lovat Lane itself is a very narrow luminaires are block switched from the systems, each serving approximately one pedestrianized street, where individual service cores to ensure that the ceiling is quarter of the total office requirements. The elevational features perhaps have a greater evenly lit, allowance for future subswitch- main insulated supply ducts drop down in impact rather than entire buildings, due to the space between the two glass skins of ing is also included at the client's request. the limited perspectives which are possible. the southern elevations and connect to the The main office pedestrian circulation floor void plenums at each level. routes are lit by continuous suspended The concept of the City Village has tubelights which follow the curve of the attracted a certain amount of comment in Air is supplied to the office space through building and illuminate the concrete soffit. the national and architectural press, not all Krantz twist air outlets which can be shut These fittings were also specially designed of it favourable, but the development is at down if they are not required or relocated and include emergency lights and low least established on the map in when the offices are rearranged. voltage dichroic spots which highlight the consequence. Air is extracted through ducts integrated concrete columns. with the luminaires and passed to header Conclusions ducts within the raised floor above, which The main electrical power telephone and The four phases of City Village were in turn connect to the main air risers in the VDU services which rise in the stair cores completed in almost exactly four years when Building M was finished in May 1985. service cores. distribute horizontally within the raised The cost will be somewhat in excess of Extract air is recirculated or exhausted in floor void to a grid of fixed junction boxes. £10m. excluding land purchase costs. varying proportions at the dictate of the From these boxes flexible cable control system. The recirculated air is connections are made to multi-service Schemes are currently being examined for Ackermann floor outlets which can be upgrading one of the original either mixed directly with outside air or hence of the site. It was decided that bored delayed the Phase 3 contractor, Wates rearranged to suit new furniture layouts refurbishments, partly as a consequence of bypasses the evaporative cooler to achieve pile foundations were suitable and a Construction Ltd., from erecting when alterations are made. comparisons made with the new buildings the required air condition supply. system was developed to cater for the scaffolding in the same narrow lane for This ability to move the electrical and air by potential tenants. Outside air is normally introduced into the eccentricity of load using tension piles. In Building AB. supply outlets proved to be a considerable We found a straightforward structural air handling units through louvres in the most cases three piles were used at each Phase 4 was again negotiated with Trollope advantage during the fitting up period when solution to suit the particular constraints of roof plantroom walls but in the winter when column, with a single pile in tension. and Colls to gain a further time advantage office layouts were amended right up to the the development and we were content to solar gains and office heat losses warm the A pre-contract trial pile was specified for in completing the entire development; this time the building was occupied. retain it after a satisfactory trial on Phase 1. air in the double glazed void, the outside air the first phase with the results also being enabled an earlier start to be made as an is taken from this space to reduce the air used for Phases 2 and 4. On Phase 3 an overlap with Phase 2 could be achieved. This had obvious advantages and left us handling plant loads. In the summer when increased factor of safety was used (2.5 JCT '80 was also used for this contract but with relatively more time to concentrate on warm air in the double glazed void would instead of 2.25) to avoid the need for a with all sub-contractors taken on as the particular problems of each phase, increase heat gains to the office space, the further test; it was calculated that the cost domestic. This seems to be becoming an such as the deep underpinning on Phase 3 void can be ventilated by opening louvres in of the resulting additional length of each and the extreme lack of verticality of the Summer gap Winter solar increasingly common client requirement the plantroom wall to encourage air exhaust damper! handling preheated pile would be less than that of a test, and and presumably one which causes some Phase 4 party walls. We also found that on movement by 'stack effect'. These louvres outside additionally would not affect the misgivings to the Joint Contracts Tribunal, all phases the structure was completed also open automatically to ventilate the programme. bearing in mind the numerous and lengthy with few problems and, where not affected cavity if smoke is detected. nternal skin -glass or Contract arrangements clauses on nomination in JCT'80. by circumstances beyond our control, partition panel Heat loss at the perimeter is offset by ahead of programme, which really speaks Ventilation hv Phases 1 and 2 were carried out under the The development for itself. finned convector radiators fed from the stack effect 1963 RIBA Form of Contract. In order to Those buildings which have been in summer compensate temperature heating system obtain some appreciable degree of overlap refurbished tend to be fairly plain, with Credits: and controlled by thermostatic valves. The between the two contracts on adjacent brick facades unadorned by the features perimeter areas are protected from Blinds in gap between sites sharing the same limited access, the Client: glass skins controlled which characterize the new City Village Guardian Royal Exchange Assurance excessive heat gains by motorized Venetian automatically by sola Heat absorbing Phase 2 contract was negotiated with buildings. They are however obviously not blinds activated by solar radiation: The glass operates as Trollope and Colls Ltd.. the contractor on unrepresentative of the original character Architect: solar collector The Thomas Saunders Partnership louvre blades are perforated for about 20% in winter and Phase 1; the latter contract had been of the area and they do possess a certain of their area and so appear transparent sun shade in awarded on the basis of a conventional elegance. The new buildings are more Quantity surveyor: summer Wicksteed. Son & Few rather than opaque and allow views to the A.tifi ,i i tender. ornate, with extensive use of stonework, M&E consultants: outside without a major heat gain problem. Phase 3 was again put out to tender, this copper cladding on roof features and Cool air inlet The Williams Sale Partnership The blinds are lowered at night and during Supply time using the 1980 JCT Form of Contract, external metalwork. The most striking Buildings D.R.S, and AB weekends in the winter months to minimize on the basis that this was a separate site building is AB. which has an octagonal Max Fordham & Partners heat loss from the office spaces. tower on the corner of Lovat Lane and the construction would not affect any Buildings Q and M As a guide to energy use the building has rights of access, etc.. granted under Phases surmounted by a tower of reconstructed Main contractor: an office area of 8,250m2, a boiler output of Outside air inlet stone topped with a copper-clad dome and 1 and 2. In the event the reverse situation Trollope & Colls Ltd. a weathervane in the form of a fishing boat. 700kW, a chiller capacity in the region of occurred: Phase 2 was completed Buildings D.Q.R.S&M (Phases 1.2&4) Part of the Monument Street facade has 400kW and maximum electrical demand of considerably behind programme and the Wates Construction Ltd. 500kVA. scaffolding to the Lovat Lane elevation also been constructed as an exact replica Building AB 19 the inner skin and outer skin which is used fitting than by structural considerations, Human beings are remarkably sensitive to General description of the building steel sections, preparation and checking of for the distribution of supply air ductwork and could have been decreased vibrations and it wasn't too difficult to Farnborough Road The building occupies a prime site at the working drawings and the actual and for maintenance access to the glass significantly by taking advantage of the calibrate the RE's dentures with Arup north-east side of the Clockhouse fabrication, tender documents were issued and blinds. The ductwork has a bright red prestressing techniques finally chosen for Acoustics' swinging needles, thus avoiding office development Roundabout close to the centre of at the end of May. The lowest tender was stelvetite finish which can be clearly seen this structure. However, their effectiveness the need for constant electronic Farnborough. The site measures roughly submitted by Octavius Atkinson who were behind the glass skin. as 'concrete lamp shades' would have been monitoring. Architects: Scott, Brownrigg and Turner 150m by 140m and has a slope of 7m from appointed towards the end of July, 10 The bronze glass outer skin as well as compromised by so doing. There were three main areas where north-east to south-west. weeks before start of erection. projecting at low level to form a canopy is At an early stage in the design a decision vibration was a potential problem: The building, with a gross floor area of To speed up construction, the steelwork raked back at high level to enclose the was taken to prestress (post-tension) the (1) Domestic houses about 100m away Svend Jensen approximately 10,000m2, has a cruciform rises directly from the foundations plantroom on the roof. In order to resolve ribs for a number of reasons: where vibrations evoked the understand• plan shape (see Fig. 2). The central area and including the stanchions in and around the the junctions resulting from this geometry, Firstly the relatively wide span and single- able concern and natural suspicion of the Peter Lunoe two of the wings are five storeys high and basement. This allows the upper floors to Pilkingtons and Doulton Glass developed a bay configuration produced rotations at the householders. the two other wings, designed to have a be completed in the shortest possible time new system of glazing for the building columns which influenced their size so that key activities such as roof which is now known commercially as the These houses were surveyed before and Introduction roof garden, are four storeys. The central disproportionately to the axial loads waterproofing, curtain walling and PilkingtonPlanar System. Sheets of 10mm after piling operations. No damage was Concrete versus steel-framed construction area is the only part of the building to have carried. By prestressing the ribs and installation of services can proceed in bronze armourplate glass, 3.6m high x 1.8m found but one resident was particularly is an argument which has been going on a basement and it also has a substantial considering the tendon profiles, column parallel with the more time-consuming wide, are held in place against aluminium concerned because the vibration was for 50 years or more. The deciding factor is plantroom on the roof. The entrance hall in moments could be adjusted and were in concrete construction in the underground mullions by six 6mm diameter countersunk causing waves in his fish tank, and his fish generally cost, which depends not only on the west wing is double storey height and fact greatly reduced. By load balancing, the ducts and ground floor. stainless steel bolts. These bolts pass were beginning to look a bit sea-sick. prices of materials and labour but also partly open to allow cars to drive up to the long-term deflection of the ribs became Substructure and ground floor through pre-drilled holes in the sheets and changes in design criteria, technical main entrance (see Figs. 3 and 4). negligible and pre-cambering unnecessary. (2) A multi-storey building, with long span The site investigation showed approx• are connected to the glass by a system of development and new construction The main core is in the central area, with and relatively flexible floors, about 200m imately 20m of Barton Sands overlying specially designed gaskets and washers. There were further advantages to be gained techniques. smaller cores which house escape stairs away. Vibration was felt particularly at the Bracklesham Beds. Settlement calcula• Only the bolts at the top corners of each such as reducing reinforcement conges• and duct risers at the end of each wing. upper levels. Since the 1950s concrete has been the tions based on static cone penetration sheet carry the vertical load of glass, the tion, but more importantly, by stressing the The planning module is 1.5m and the wings obvious choice for medium-rise buildings in tests confirmed that it was acceptable to remainder being used solely to transfer tendons in two stages, the formwork and (3) The adjacent supermarket, against the UK but over the last few years steel has have the normal office width of 13.5m with found the building at high level in the horizontal wind loads to the aluminium staging to the ribs could be removed after which we were piling to within 3m. It was made a strong come-back. central columns dividing it into 6 and 7.5m Barton Sands with a safe bearing pressure mullions. This method of fixing allowed the about three days. This was particularly necessary to change the pile type within This is partly due to the current low, it could spans. The longitudinal column spacing is of 200kN/m2. glass sheets to be considered as separate important since the ribs are exposed and 12m of this building to a smaller diameter be claimed artificially low, cost of steel but 6m increasing to 7.5m adjacent to the plates which could be located in space to therefore required particularly high quality, driven pile with steel permanent lining tube. the most significant factor is the use of central area. For ease of construction, strip footings, achieve the required facetted angles, and expensive GRP moulds. The moulds were of Once again we used the vibration composite construction with metal sheet The external elevations are clad inCoolite running the length of the wings on the the gaps between were then simply sealed trough profile and, for ease of handling, monitoring equipment to enable us to find a decking. mirror glass which reflects 83% of solar column lines, were used instead of with gun-applied silicone sealant. The made in five sections from a one-piece reasonable driving technique. As luck master. Each set of moulds was marked to This form of construction is common in heat. The cladding is made with structural individual pads. Adjacent to the basement erection of the glazing proved to be would have it the 'wines and spirits' counter ensure their correct match on site, where North America and most of the develop• silicone double-glazed units and is claimed the strip footings were stepped down using relatively easy and the whole system was along the wall adjacent to our site. mass concrete. they were butted together and carefully ments which have taken place over the last to be the first project of any size in Britain provided a simple solution to what could Using the vibration monitoring equipment have been a complicated problem. aligned on the staging. They were then 10 years have been pioneered in the United using silicone bonding on all four edges. The basement is close to the water table we were able to observe that the The rear elevations of the offices, which bolted together using foam strip between States. These include techniques for The exposed columns have an aluminium and as the ground is slightly acidic, with Ph permissible vibration outlined inD/N 4750 face the garden, are sealed with a more the butting faces, but no tape was used as coincided consistently and reliably with a through-deck stud welding and also casing with polyester power finish. Solid values down to 4.5, an external membrane conventional system of single, clear, it was considered that this would draw barely perceivable excitement of the improvements in steel sheet profile with panels with similar finish are also used at was used to provide watertight conditions toughened, glass sheets in aluminium attention to the joints when the ribs were Advocaat bottles, which increased specially designed indentures to increase the secondary cores, alternating with vision and at the same time protect the concrete frames with solid, insulated spandrel finally painted. All post-tensioning noticeably with increasing vibration levels. the load-bearing capacity of the sheet itself panels of mirror glass. from acid attacks. panels at each floor level and at the roof. hardware, fixing and stressing was by PSC Asking the RE to stare at rows of Advocaat and improve the shear bond properties The building is fully air-conditioned with a The basement excavation was done in open VAV system using ceiling-mounted slot Motorized blinds are also provided on the Slabstress using one 7k/13 tendon per rib bottles for hours on end during piling between the decking and concrete. cut with steeply battered side slopes up to diffusers. Heating is provided separately by east and west segments of the elevation to with recessed live end anchorages located operations is admittedly an unusual Within the UK there is now a considerable 7m deep. When wet, the Barton Sands turn specially designed perimeter-mounted control glare from morning and evening in the external face of the outer perimeter request. However, it enabled him to meet interest in composite structures encourag• into slurry and the excavations were radiant panels where the piped water sun. beam. The tendons were fully bonded, of several 'interesting people' and he is now ed by CIRIA and Constrado who have therefore protected by polythene sheets services, together with electrical services, parabolic profile, and stressed in two well practiced in Zen and Kendo:- the 'Way published a number of design guides, and a system of drainage channels. are distributed through the raised access Structural design stages at three and 14 days respectively. of the Bottles'. standards and technical notes. The suspended slab over the basement is floor. The section drawing shows the principal 325mm solid reinforced concrete. The The fibreglass moulds were by Barnes Not all methods of measurement require Composite construction does offer a structure to be arranged as a single portal ground floor slabs in the wings incorporate Plastics and the superstructure subcon• number of genuine advantages but some of Within the 1.8ha site there is a circulatory frame, four storeys high. gauges and dials. underground ducts which carry air- tractor was Gleeson. the claims made on its behalf appear to be road system and parking for 333 cars It is built entirely of in situ concrete and It should be explained at this point that we conditioning and other services between overstated, particularly as regards capital arranged in terraces separated by planting. comprises ribs spanning 14.4m between It is worth noting yet again that where a were interpreting vibration readings in the basement and the secondary cores at cost, in our experience it is now standard The external works also include a number perimeter ring beams, which are in turn project contains some unusual aspects, accordance withD//V 4750 which contains a the end of the wings. procedure to compare steel and concrete at of retaining walls and a 21m by 11m shallow supported on circular columns at either these usually perform well since they are fairly arbitrary and very global set of figures the early scheme design stage and in pool, an architectural feature which There are a couple of structural features in 5.4m or 7.2m centres. The curved section of given the attention they deserve. In this for different building types. case the post-tensioning and construction recent exercises of this type we have, in doubles as a regulator for the surface water the main entrance hall. The staircase to the the plan has radii of 14.4m and 28.8m to the However, the main object of using this and alignment of the formwork all each case, found the concrete structure to drainage system. first floor gallery is a thin helical slab inner and outer ring beams respectively. equipment was twofold: be cheaper in actual construction cost. Contract and programme which, supported only at the top and The ribs are spaced at 1.8m intervals along performed smoothly, accurately and rapidly. Firstly, to record the effects of adjusting However, once the cost benefit of the From the start the client made it clear that bottom, curves through 180 degrees. As a the outer perimeter closing up to 0.9m the driving technique in order to minimize shorter construction period for the steel he was looking not just for a strict budget visual counterpoint to this stair there is a along the inner perimeter. Their depth was Substructure vibration, whilst still achieving reasonable frame is assessed, this picture can change. but also for a tight overall programme to 'water feature', a helical reinforced determined more because of their A water table about 1.5m below ground driving progress. Concrete and steel are of course not give earliest possible completion. concrete cantilever, with a water cascade integration with the lighting/extract duct level, Ph values typically around 3.5, and a Secondly, as a public relations exercise so directly interchangeable; each project must Scheme designs started in January 1983. and planting. The formwork for both these site overlain by nearly 1m of peaty clay that all the 'interested' parties could see be considered individually as the general The studies of concrete and steel options structures, which can just be seen behind / ensured that the substructure required that we were taking the problem seriously. form of the building and choice of structure quickly showed that a composite steel the curved glazing in Fig. 3, was quite some thought. For some reason most people seem are interrelated. Composite construction structure would result in a two months complex and the contractor made a very The subsoil was basically silty sand peculiarly reassured by the sight of will offer maximum advantage if the saving in construction time and that the good job of the construction. overlaying gravels and because of the close someone with a box full of dials, aerials, following situations apply: financial benefit of an early completion Design of the superstructure proximity of existing buildings we would headphones, etc: the technological witch• completely outweighed the additional cost (1) Rectangular plan layout with repetitive At the time we did the design the composite have considered flight augered, grout doctor, but still, the techniques proved of the steel structure. elements beams/profiled metal decking method of intrusion piles (eg: Dowett Prepakt) had it valuable and successful on both counts. The site start was fixed for 15 August 1983 (2) No (or very small) cantilevers building was still very new to this country. not been for the acidity of the ground. We with a 65-week contract period. To get a Consequently up-to-date design methods Services (3) All steelwork within the external finally opted for driven in situ end bearing contractor abroad at an early stage a were not yet covered by British Standards. cladding to avoid concrete encasement piles with rigid PVC tubes encasing the Air conditioning Preliminary Enquiry Document, fairly We based our design on the 1983 CIRIA shafts. This at least seemed to provide a (4) Lightweight curtain wall cladding which The underfloor air conditioning system, similar to a Bill of Approximate Quantities, Report Composite construction using 1 solution to the ground water and acidity using the raised floor as a supply air can be erected without scaffolding was prepared in March and this formed the profiled steel decking. This document is I problems, but raised another problem- plenum, was designed for an adaptable (5) Finishes of dry construction which can basis for appointing Costain Construction supported by various research data and vibration. open plan office which can respond to the be put up quickly Ltd. as main contractor. During the design technical articles, particularly as regards The appointed piling sub-contractor, rearrangement of rooms and internal heat process Costains were involved in the shear studs/concrete interaction, and is (6) No severe height limitations (for spans Frankipile, had piled the adjacent site sources without major modifications. planning and programming, advised the generally in line with the ECCS European in the 6 to 7.5m range the structural without undue vibration problems, but A program was developed to analyze the design team on constructional aspects and Recommendations. floor depth increases by about 150mm monitoring during our trial pile test room thermal dynamics, taking into attended meetings with prospective sub• when compared with flat slabs). Full plastic design is used for checking indicated that we would have to modify the account the large thermal capacity of the One building, where most of those points contractors. ultimate strengths, with partial safety driving techniques in order to limit ground- concrete areas presented to the space by were fulfilled and where the comparison Fig. 5 shows the construction programme factors for loads and materials similar to borne vibrations. This was accomplished by the structural ribs. As the heat gain to the L. clearly favoured a steel structure, is the for the structural work in a slightly those in CP110. Using the 'partial- reducing the mandril drop at various stages office space reaches a peak during the day recently completed Farnborough Office simplified form. Erection of the steelwork interaction' method of design as described Fig. 10 during driving, whilst Arup Acoustics moni• the resultant temperature swing is limited Development for County and District was planned to commence seven weeks in the above CIRIA Report, the ultimate Plantroom at roof level tored the effect upon vibration at various by heat transfer to the cooler concrete Properties Ltd. after site start. To allow for the ordering of steelwork and concrete stresses are first locations using their magic black boxes. which reduces the capacity required from The inner skin consists of both glazed and checked for a full plastic distribution and economic and it is also the maximum per• entrance hall, see Fig. 4. All stanchions solid panels which are interchangeable to the shear connector requirements for this mitted span under GLC regulations when here are concrete-encased and designed as suit varying office layouts. The 1m wide are then calculated. Where appropriate the adopting a Restricted Fire Engineering such. The encasement was most important space between through which the main air number of shear connectors may be approach to the decking. in reducing the slenderness ratio of these UJ ml supply ducts run, contains motorized reduced which effectively reduces the Figs. 6 and 7 (overleaf) show the structural columns. Venetian blinds with finely perforated concrete stresses and increases steel arrangement for a typical bay in the wings. By efficient design of the steelwork, both in blocks to filter sunlight to the interiors. stresses from the fully composite The secondary beams are 305mm deep UB the overall arrangement and of the The 'U'-shaped plan encloses a garden at condition. This is then followed by a sections and the primary beams 356mm individual members, the tonnage required first floor level. Main circulation at each number of serviceability checks to ensure UB s. all in grade 50 steel. The metal for the building was kept very low. The level is along the shorter garden elevation that the steelwork stresses under wet decking is Holorib with cold formed edge weight of steelwork members equates to * ftir • * Restarant with direct access to the open office concrete, short and long-term deflections trims in galvanized steel, strapped back to 35 kg/m2, a figure which compares very - PL -...-..ill. ,$M yya spaces. Enclosed offices are located along are satisfactory. the sheeting. The overall thickness of the I I — I I I I I I — I I I I I I favourably with other steel-framed the outer perimeter where they have their deck is 125mm with normal grade 30 buildings. own outlook and are not disturbed by the By elastic design the shear connector concrete. pedestrian route. These private offices are requirement varies along the length of the Steelwork connections While the general wing beams had an For the steelwork connections we followed Fig. 5 formed from glazed or solid partition panels beam but using plastic design the studs efficient balance of concrete and steel for the normal practice of showing the Section similar to those of the inner skin with can be placed at uniform spacing with the composite design, different considerations unframed glazing at high level fitting into proviso that a serviceability check must be structural requirements, in terms of design applied to many of the core beams. Loads grooves in the ceiling beams. At first floor carried out on the peak stud force at reactions and moments, on a specific set of were heavier because of blockwork walls garden level the main circulation route working loads. In this country a standard drawings, enabling the fabricator to design and screeded rather than modular raised connects the three office cores to the size and type of connector is almost and detail the joints to his own preferred floors. Services openings and lift shafts methods. The steelwork connections were " " "i J^LT—' dining area which is built against the brick invariably used, a 100mm high by 19mm reduced the composite action available Bar wall enclosing the garden on the north side. diameter headed stud made from low required to take the full beam reactions and Ill 1 1 -r-t— . H from slabs and, of course, the services Behind this wall are the bar and servery carbon St 37-3K mild steel to the German moments as we considered little engineers particularly wanted to maximize with the coffee lounge and kitchen on the Standard DIN 17100. The advantage of this contribution could be gained from the the zone available for themselves with a level directly above. is that the stud has good welding qualities, concrete of the composite section. consequent minimization of structural its general properties and installation As a rule secondary beams were designed depth. Judicious re-arrangement of beam The ground floor encloses a pedestrian mall requirements are well established and the as pinned each end, perimeter and spine layouts plus a little extra reinforcement of with commercial lettable space on both necessary equipment for site welding is beams as having partial fixity. The the critical areas enabled us to satisfy all sides and accommodates the main office readily available. The stud-to-concrete com• fabricator chose not to have bearing cleats the requirements. entrance, computer suite, covered car park, pressive force is dependent on the concrete but end plates for all beams, and designed stores and some of the mechanical and geometry between adjacent decking ribs Columns were designed to BS 449, typical a set of joint types following standard electrical plant. The office entrance is a and the concrete grade and type. internal stanchions being 254 x254mm UC principles. Secondary beam connections double height space which opens up to the sections and perimeter stanchions were entirely within the steelwork depth, first floor pedestrian route and allows One of our early studies was to investigate 203 x203mm UC's. On the north, east and primary beam connections utilized the glimpses of the shrubs and trees in the the steelwork arrangements for secondary south wings the cladding steps in 900mm depth available within the concrete zone. garden beyond. It is located to the east of beams at 2m, 2.5m or 3.0m centres. These below the first floor as can be seen in Fig. For those situations where stanchion web Fig. 6 the pedestrian mall and is separated from it spacings cover the practical range of spans 10, so the perimeter stanchions become stiffeners were necessary, he used web First floor plan by the central stair core. The loading bay is for the profiled decking; any greater external and are concrete-encased. On the thickening plates on the principles in the north-east corner of the plan with spacing would require temporary propping west wing the cladding runs across the developed in recent years and shown in the direct access to the goods lift which serves of the decking during concreting. Our study soffit of the second floor, giving the clear Constrado Manual of Connection Design. all the office floors and the kitchen at showed the 3.0m spacing to be the most double-storey height area in front of the By comparison with traditional stiffeners at second floor level. Although the building has a 'U'-shaped plan Fig. 1 it is basically a linear structure in which • - Site plan concrete ribs span between concrete beams. The surfaces of the ribs are painted Fig. 2 in the offices and are evenly lit by specially p Typical secondary core View from north-east designed luminaires. This has the effect of making the ceiling float and appear higher Fig. 3 than the actual dimension of 2.4m from xtent of Expansion joints Main entrance hall finished floor to soffit. The main stairs and t, rpof plant rDOm lifts are located at the centre of the 'U' with Fig. 4 escape stairs and toilets at the ends of Erection of steel each arm. Between the service cores on the frame three upper floors are constant 14.40m wide Central Cor (Photo: Costain) office spaces giving discreet lettable areas Balancing typical floor] of approximately 800m2. DOOl Major elements of service plant are accommodated in the high level plantroom which is located on the roof between the Fig. 7 central and eastern service cores. The Ground floor plan plantrooms connect to the space between

(Figs. 2-3 Photos: Ernie Hills)

Bypass duct

Return] Supply fan plant

Warm air Return riser return riser in core — » ——i i 1 ._t—

Warm air Cool a return duct iupply

Warm air outlet

Fig. 8 Fig. 9 Radial floor beams under construction Cross-section showing air distribution right angles to the web, this method is of Each step of the flight is formed from a audible range, the low frequencies can be great benefit wl-.ere beams are connected steel plate bent to give a 75mm deep tray, felt and there is a danger that they may to the stanchion from two or more which is then filled with normal concrete induce high or audible frequencies in some directions. after steelwork erection. This gives the final part of the building, even far away from the Stanchion splices were initially stipulated stair ready for carpeting. source. To combat this the roof plantroom as being to full strength of the section, For the semi-circular landings the primary has a floating floor made with an bearing in mind that most stanchions were steelwork is two 150mm square hollow independent, mesh reinforced concrete designed to 90-95% of their capacity and section members, welded to give a T shape slab cast on a metal decking, which is some a little more. The fabricator chose to in plan. The outer edge is a curved supported from the structural floor by splice stanchions 500mm above second 100 x 100mm angle, acting both as edge resilient rubber pads. Apart from acting as floor level, and proposed end bearing for former and structural member. Holorib a structural isolator the floating slab adds axial load with normal bolting/plates for profiled decking and concrete then to the general mass of the floor structure moment capacity. After inspecting his complete the landing on site, again ready and provides high frequency attenuation works and the quality of machining, we for carpeting. Corrosion and fire protection agreed to the end-bearing proposal. To The stairs and landings are simple in The question of corrosion protection of the assist him we also gave more specific concept and construction. What is not so steelwork was discussed with the client at design values for stanchion moments at his obvious is the care required in design and a very early stage and it was agreed that chosen splice locations, enabling him to detailing to achieve this. Stairs often throw although it was basically in a dry, internal minimize the bolting/plates requirements. up problems disproportionate to the environment some form of protection Stability amount of work in them, and the ones in should be provided. All the internal this building were no exception. For steelwork, apart from the top flange of For structural stability the cruciform beams to which shear studs are welded, building shape is very suitable. Diagonal example the secondary core landings lie outside the perimeter line of stanchions, has been painted with a two-pack epoxy bracing is provided for both directions in primer. In addition the members along the the central core and for the transverse giving a most distinctive feature to the final building. However, the resultant force perimeter, which are more likely to become direction in the escape stair cores, at the damp, were given an MIO barrier coat. end of each wing. The locations of diagonal eccentricities, at mid-height level on the stanchions, proved quite a problem. Some The superstructure was required to have a members had to be co-ordinated with fire resistance of one hour and for internal services ducts and doorways into the cores, specially-shaped brackets, fitting com• pletely within the stanchion flanges so as beams and columns this was achieved by a so each elevation of bracing is designed as vermiculite spray, Mandolite P20, and by an N-truss arrangement. To allow for any not to protrude either into the cladding zone or the stairwell, were the answer. fire blankets at the expansion joints. direction of wind loading, diagonal The external stanchions at ground and first members were designed both for tension Structure-borne noise and vibration The steel-framed structure, being lighter floor were encased in concrete, with a and compression, using square hollow 50mm mesh reinforced cover, after section steelwork. and generally more flexible with a lower damping capacity than that of an erection. Expansion joints are provided towards the equivalent concrete structure, is more inner end of three of the wings, at locations susceptible to vibration. However, As far as the deck is concerned a Restricted chosen to give simple detailing. To permit calculations indicated that the structural Fire Engineering Approach was adopted to longitudinal movement but provide response of the building is perfectly calculate the extra fire reinforcement transverse stability the joints were made as which, in addition to the A98 mesh in the satisfactory for normal office use. The office entrance was to be separate into two and, although the site was left over sliding joints with dowels in the concrete top of the slab, amounted to an 8mm bar in from the entrance to the shopping mall and from the Kingsmead development, it is the deck. Longitudinal stability for these wings Although most machines and items of plant the bottom of each rib, ie at 150mm to have a clear identity for visitors to the centre of focus for people entering the is provided by the spine beams and vibrate at frequencies well below the spacing. building. centre by bus or from the public car parks columns acting as moment frames. S3 84 to the south, and for motorists coming As the west wing stanchions rise clear up to Aug Sap Del tov Dec Jan Feb Mar Apt May The client also requested that special down the hill into Farnborough on the A325 the second floor, it was logical not to have Structure programme ! attention was to be paid to the problems of Set up site traffic noise and solar gain and to the long- from Aldershot. an expansion joint for this wing but provide Sill durance and excavate longitudinal stability to it from the central Concrete footings : Wingi term running costs. The Royal Aircraft Establishment is located core. Providing bracing to the wing in this Concrete lootings Central The site about three quarters of a mile away Drainage under building towards the south-west and low flying manner is also of benefit in the design of Norih&Wett South & East The site is one acre of level land with the the individual stanchions, because of their Erect sttel frame Wings — — northern boundary enclosed by the 5.0m aircraft pass quite close to the southern E iHI t steal frame Central South ft East boundary when they approach the runway. slenderness. Concrete superstructure floors Wings • a Mm high red brick wall of the Kingsmead Concrete superstructure floors Central Shopping Centre. Although predominantly The design Stairs Hoot finishes a two-storey development, it also includes It was clear that the new building would The concept of straightforward steel B. Slab. Welti an eight-storey office block and a multi• have considerable impact on its erection, concrete cast on permanent Concrete central area Ground floor slab storey car park which dominate the scale of surroundings because of the key position of decking and no propping, is carried the surrounding area. the site. We therefore decided that it should throughout the superstructure including Concrete casing to eiternel columns contribute an element of order and visual the stairs in the central core and at the end The site is bordered by roads on the other _FirtpfO0fmg spray tojeemi and internet columns interest to the undisciplined and rather of each wing. Fig. 9 shows a stair core three sides; the A325 Farnborough Road Curtain walling Support brackets drab character of the neighbourhood. during construction. runs parallel with the eastern boundary linking Farnborough, Aldershot and The solution we adopted was a four-storey Each flight is a shop-fabricated steelwork Farnham with the M3 motorway, and to the 'U'-shaped office building which closely unit, bolted on site to the landing beams. south are two extensive public car parks follows the southern site boundaries and which abuts a high brick wall to the north Fig. 5 and a large roundabout. A few isolated Cladding Corridor Cladding mature trees offer a little relief to the separating the new development from the zone Office zone zone Office zone zone Programme for the structural works predominantly hard, noisy surroundings. shopping centre. Fig. 6 An existing public right-of-way connected Because of the site environment and the the shopping centre with the bus stop on need to protect the office space from traffic Layout of typical bay the southern boundary and divided the site noise and solar gain, it was considered Fig. 7 essential to seal the outer perimeter and Typical cross-section through deck therefore to air condition the interior. This 305x102x33 U.B. 305 x 102 x 25 U.B. led to the structure and the elevation -e> Cladding: playing a major part in the environmental Mullions supported by brackets services design concept for the building. bolted to slab All office spaces have raised floors for the distribution of computer cabling as well as Aluminium slab edge former 190x 100 high shear studs electrical and telephone services and this stayed at intervals to decking single line on every beam floor void is used as the supply air plenum for conditioned air supplied through floor- n n n n n n njI n n n Fig. 1 mounted air diffusers. 203x203x46 U.C. 254x254x 73 U.C. Detail showing the double skin The outer perimeter of the offices is do do enclosed within a double skin elevation. it Fig. 2 The outer skin is totally glazed with bronze r 1 The south elevation overlooking tinted glass to provide consistent, easily the car park maintainable weather protection. This skin Fig. 3 -i—I Perimeter beam Secondary beam Spine beam is facetted so that its reflective surface Site plan 356x127 x33 U.B. 305 x 102 x 33 (or 251 U.R 356 x127 x 39 U.B. responds to variations in light and changes 7.5 m 6.0 m Fig. 4 of view. At first floor the skin projects to Office interior form a glass canopy over the pavement. Vol.20 No.2 Summer 1985 Contents Practical matters decking plus a layer of edge trim occurred, Published by With traditional concrete construction the studs detached. The site test seems Ove Arup Partnership 13 Fitzroy Street. London W1P 6BQ there are practical aspects which, because crude but appears to be quite effective. THEARUP they are so familiar, are often taken for Large holes for lifts and such like are granted by the design team or left in the formed by the decking laid to suit with edge Editor Peter Hoggett capable hands of site staff and the trim all round. Smaller holes for services Art Editor Desmond Wyeth FSIAD can more conveniently be formed by JOURNAL Assistant Editor David Brown contractor. Similarly with composite construction there are many practical running the decking through, boxing out Leslie & Godwin, Farnborough, aspects but in contrast these should be prior to concreting, then cutting the deck by Mike Bonner and Terry Raggett considered by the design team. afterwards. Steelwork erectors are permitted to work Because of the timescale of erection and Ronald Stewart Jenkins: without all the safety rails required for the comparatively small quantities engineer and mathematician, general labour gangs. This is one involved, the contractor will generally be by Ronald Hobbs advantage in having the profiled decking looking to pour quite large areas of included with the steelwork sub-contract, concrete at a time. On Farnborough where The Merlin Hotel, 14 so that the erectors also lay the decking. the concrete was pumped and power- Perth, Western Australia, However safety rails will then be required floated, the contractor was aiming to by Keith Pollock before reinforcement fixing and concreting. concrete one floor per day in each wing. The spacing of shear studs should be a Although this was a little optimistic for the City site: Lovat Lane, 18 multiple of, or the same as, the decking rib first wing where a learning curve situation by Deborah Lazarus centres where the decking crosses the applied, he did achieve it for each of the last beam. Conversely where the decking is two wings. Farnborough Road office development, 20 parallel to a beam, it should be arranged so Conclusion by Svend Jensen and Peter Lunoe that the ribs are spaced equidistant about The Farnborough Office Development has the centreline of the beam clearly demonstrated some of the Site testing of the shear studs is very advantages which can be gained by using simple. A small proportion are bent over to composite construction in the right 15° from the vertical, usually with an odd circumstances: given the high standards length of scaffold tube. If a stud detaches, required, the building has been completed or a visual inspection shows any fractures quickly and at a relatively low cost. in the weld, then it is condemned. On this project we found that generally studs Credits welded through a single layer of decking Client: were all sound, whereas in the few places County and District Properties Ltd. where two layers of decking or a layer of Front cover: Leslie & Godwin building: main office entrance (Photo: Peter Cook: Designed by: Arup Associates) Architects: Back cover: Ronald Jenkins Scott. Brownrigg and Turner Fig. 8 Quantity surveyor: Roadway under west wing Banks. Wood and Partners (Photo: Ernie Hills) Services consultant: Leslie & Godwin, Fig. 9 Michael Aukett Associates Escape stair in wings Landscape consultant: Farnborough (Photo: Svend Jensen) Eachus Huckson Partnership Main contractor: Fig. 10 Costain Construction Ltd. Arup Associates View along south wing Steelwork sub-contractor: Group 5 (Photo: Ernie Hills) Octavius Atkinson & Sons Ltd. Mike Bonner V Terry Raggett

The brief The Leslie & Godwin Group commissioned Arup Associates in September 1978 for the design of an owner-occupied office building totalling about 9,500m2 at Farnborough, Hampshire. The brief required a mixture of deep and shallow office accommodation with lettable commercial space at ground floor level. Outline proposals were approved by Leslie & Godwin in December 1978 but because of reorganization within their company, the scheme was temporarily halted. In March 1980 ownership of the proposed building was acquired by the Imperial Group Pension Trust Ltd. who, through their agents Richard Ellis, amended the brief to one considered more suitable for a 4 speculative building. The office space was > to be of a constant width of not more than 18m which could incorporate enclosed offices at the outer perimeter and also capable of being subdivided into separate lettable areas of between 600m2 to 850m2. The dining area was required to cater for a total of 450 people in three separate sittings and was to be provided with separate coffee lounge and bar. The ground floor had to include the pedestrian right-of-way developed into an enclosed shopping mall with as much commercial lettable space as possible on each side. In addition, covered space for 20 cars was required as part of the site THE ARUP JOURNAL

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SUMMER 1985

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