THE ARUP JOURNAL

2/~993 Front cover: The Karasu Viaduct, Turkey. (Photo: © STFA) Back cover: THEARUP Interior of bus station, Chur. (Photo· Richard Brosi) JOURNAL Vol 28 No.2 Editor: 2/1993 David J. Brown Art Editor: Desmond Wyeth FCSD Published by Ove Arup Partnership Deputy Editor: 13 Fitzroy Street, Hell!ne Murphy London Editorial Assistant: W1P6BQ Kris Buglear 3 Chur station roof Ove Arup & Partners designed the glazed steel barrel-vault roof Alastair Hughes above the important new transport interchange at Chur in Switzerland. The structural concept for the tied arch was the work of Peter Rice. The roof recently won the Swiss ECCS (European Convention for Steel Construction) Award for 1993.

8 Mirror mirror In the 19th century British engineering had a clear. strong. and on the wall ..• positive public image; today this has been lost. This article looks at How fair is the the causes of the decline in engineers' standing, and suggests engineer's image? some remedies. Sir Jack Zunz

12 River Aire Footbridge This prefabricated steel cable-stayed footbridge in Leeds was Colin Harris designed by the local Ove Arup & Partners office; both the 19m mast Mark Steele and the 56m deck were erected in a single day.

14 The Weardale Line An Arup team was commissioned by local authorities to examine the Adrian Gurney possibilities for development of a railway line in the upper valley of Ed Humphreys the River Wear, in County Durham. One section was to be closed, and among Arups' proposals was its re-opening as a steam line for tourists.

16 St. George's House, This early 20th century example of reinforced concrete construction, Manchester originally built for the YMCA. has been refurbished as high quality Geoff Bickerton office accommodation. Ove Arup & Partners Manchester designed Steve Burrows the new works following a close study of the original structure. Mark Elsegood

20 The Kinali-Sakarya A joint venture including Ove Arup & Partners supervised the Motorway, Turkey construction of nearly 200km of motorway in Turkey. as well as Alan Hughes considerable associated viaduct and tunnel works. A length of 45km Andrew Lord was also designed by the joint venture.

2 1. The 'hub' casting with mountains behind. Introduction gradients, tunnels, viaducts and helical The new station root which has recently been loops, the Rhatische-Bahn is no mere tourist completed in Chur, Switzerland, is worthy of railway but the everyday line of communica­ notice on several counts. It is an impressive tion for the places it connects. demonstration of the Swiss commitment to Not every community is on the railway, but quality in public transport. It is also the fruit of those which are not are well served by the an unusual degree of international collabora­ other transport system, the postbuses of the tion, and in this respect the project may offer PTI. These distinctive yellow coaches are co­ a pattern for the future. ordinated with the railway seNices, and run Chur is the capital of the GraubOnden canton with the same precision. Deregulation is an in eastern Switzerland - the largest, and alien concept in Switzerland, and it is quite arguably the most mountainous. in the feder­ taken for granted that the same organization ation . As well as some of the most popular should run the rural buses as the national and fashionable winter sports resorts (Arosa, post and telecommunications services. Davos. St Moritz}, the region contains remote The Chur project, of which the station roof is alpine valleys in which the Romansh lan­ only the most visible part. originated in a 1985 guage (Switzerland's fourth) suNives. Chur architectural competition for the whole area itself has a long history based since pre­ round the station, including associated postal Roman times on its strategic position in com­ buildings. Better integration of facilities. a mand of !rans-alpine routes. Today, one visual upgrade, and more effective use of rail­ might describe it as a substantial town rather way land were the objectives. The competi­ than a city, but its importance as a transporta­ tion was sponsored by the three main users tion centre is out of proportion to its size. - PTI, RhB and SBB (the federal railways), The station at Chur is an interchange point together with the municipality. The lead client between inter-city trains from Zurich and be­ and project manager was the PTI, an organi­ yond. which terminate here, and the regional zation with an impressive record of public transport network. This consists of two main sector architectural patronage. SBB is also components. The 1m gauge RMtische-Bahn active in this field - recent station recon­ (RhB) was constructed in the late 19th and structions by Calatrava in Lucerne and Zurich early 20th centuries. Legendary tor its steep 2. Chur location map. (Stadelhofen) are noteworthy. 3 3. Right: Architects' model. 4. Below: Bird's.eye view of the competition· winning project. The original station building is in green; new postal buildings under construction are in blue. The red buildings are planned commercial developments on surplus railway land. The portion of the roof which has been completed is at the left·hand end and represents rather less than half of the longer section. It covers a new bus station built over the tracks.

Architectural concept The challenge was to interpose a minimum of trussed arches popular in 19th century rail· The competition was won by the architectural obstruction between the passenger and the way stations. but again the comparison joint venture of Richard Brosi and Robert view. A fully·glazed barrel roof should mean should not be overstretched. Its more direct Obrist, based at Chur and St Moritz respec­ just that, with no special treatment at the context is the line of development of the work tively. Their scheme proposed a glazed roof apex. Since there is locally zero slope at this of Peter Rice. whose conception it was. over the entire station, with a bus deck built point, a high performance glazing system, Although agreeably simple in appearance, above the tracks at the south end to facilitate probably involving silicone sealing, was such structures call for a degree of analytical interchange. Two new buildings and a system called for. RFR (Paris) was brought into the sophistication not available in pre-computer of subways for postal traffic were also team to undertake the design of this aspect. days. This, and the materials used, confirm included. The first phase, now complete, Structural concept the structure as one which is not in any sense includes one of the buildings, the bus deck, The structural solution chosen has been backward·looking. and rather less than half the length of roof described as a 'bicycle wheel arch' (although Two variants of the bicycle wheel arch were ultimately envisaged. it does not stand too much comparison with a developed - one a simple two-dimensional The architects' vision was of a fully glazed real bicycle wheel either in appearance or in version and the other having the arch split barrel·shaped roof, covering most of the structural action). It is a tied arch, with inter· into two members which diverge and recon· tracks in a single span of just over 50m. This mediate radial ties providing restraint against verge, giving curvature on plan as well as in would, besides protecting users from the buckling to the principal compression mem· elevation. Besides the gain in visual richness, weather, act as a unifying feature and give ber. It has something of the flavour of the this obviated the need for bracing. The the station an identity hitherto lacking. weight of steel is if anything less, but fabrica· Although the station building itself, parallel to lion costs are inevitably higher since more the tracks on the town side, is a 19th century members and more joints are involved. Both construction of some character, the platform variants were tendered; in the event the areas lacked distinction. The tracks are three-dimensional one, dubbed the Zitronen· almost straight over the length of the plat­ schnitz (lemon wedge) was chosen, and this forms, and a classical steel arch design was has been constructed. General opinion is that judged appropriate. Feeling that inspiration this was the right decision. That it was taken could be gained from the tradition of 19th is to the credit of the client; in effect an aes· century train sheds in the UK, the architects thetic premium was accepted. invited Ove Arup & Partners to join the design The Zitronenschnitz is formed by two princi­ team. A study tour was arranged, including pal tubular members each curved to a con­ Liverpool Lime Street as well as the obvious stant radius in one plane. Because they lean London termini and the glasshouses at Kew. relative to one another the profile of the roof, It should be emphasized that the intention viewed in cross section. is slightly elliptical was not to recreate a period piece - the new (though the deviation from circularity is less roof was to be of its time, using modern than 25mm). Tie geometry relates to purlin materials to the best effect. A special empha­ locations. which in turn are dictated by equal sis was placed on transparency - unlike subdivisions of the glazed surface to give most British stations Chur is closely sur· standard-sized panes. All this geometrical rounded by mountains, which had not to be 6. Architect's sketch complexity is handled with relative ease by obscured by the new roof. of the 'bicycle wheel' origin of the arch. CAD systems, but would have been to say

5. The new roof dwarfs the existing station buildings. 7. View from an adjacent building: the external rails arrest snow and provide a track for the access equipment. 8. A view embracing virtually the whole of the glazed span produces a slightly peculiar perspective effect, but emphasizes the distinction between skeleton and skin. 9. The glazing system features silicone butt joints in the longitudinal direction.

4 the least a deterrent without them ; perhaps th is structure and others on our screens today will be looked back on as children of their time, in the same way as the •45• set­ square' architecture of the '60s is now regarded! The choice of the primary spanning system was only the first step in the design process, which involved close interaction between London, Paris and St Moritz. The most appro­ priate and etticient arch member was a 406mm diameter circular hollow section in grade 50 steel. It was decided that the secondary structure should also be tubular, and run longitudinally at approximately 2m centres. Since these purlins also act as ties between the divergent arch pairs of the Zitronenschnitz, they should occupy the same plane. However the skin of the roof, the glazing system, had to be set distinctly above the plane of the skeleton so as to make a clear differentiation between the two. Glazing system Fundamental decisions about the glazing system were that the material should be glass - nothing else would maintain the desired transparency in the long term - and that flat panes, 2m long , would make an acceptable faceted approximation to the curve of the roof. Laminated glass was required for safety, but double glazing was unnecessary - the roof is only a cover, with no sides. Any slight condensation was considered acceptable. For transparency, and in order not to impede the flow of rainwater down the slope, silicone butt joints are used in the longitudinal direc­ tion. Conventional glazing bars and capping sections are used in the 'hoop' direction. This supports the visual differentiation between structure and cladding system, since no structural parts run in this direction. With the uppermost panes inclined at little more than 1• to the horizontal, it is hoped that no unsightly puddling (leading to dirt encrus­ tation) will occur. Toughened glass (as one leaf in the laminate) was considered but ruled out on cost grounds. Ordinary laminated glass, though less resistant to accidental breakage, has performed well in similar over­ head situations, and the tenacity of the sili­ cone on two sides can be expected to enhance the safety of the system. RFR devised a glazing bar detail which accommodates, in the gap between the panes of glass, slim brackets to support the external snow rails. These are necessary to limit ·avalanching ' of snow down the slope (which at its steepest 1s 40°) and also serve as tracks for the access gantry for cleaning and repair, which is essential equipment for a roof of th is type. With the exception of the extruded capping piece, all the metal com­ ponents associated with the glazing system are unpainted stainless steel , which further differentiates them from the white-painted structural steelwork. 8 7 9

5 10 11 Support structure apart. Each column is composed of a pair of The columns themselves act as cantilevers The spacing of the Zitronenschnitz elements 406mm diameter circular hollow sections, from below, strong and stiff enough to resist is approximately 7.5m, which allows the tubu­ battened together at intervals, and reaches lateral wind forces but not so stiff as to gener­ lar purlins to be kept appreciably smaller than out, in the shape of two 45• triangles, to sup­ ate untoward resistance to thermal expansion the arch members. To minimize impeding cir­ port the ends of two Zitronenschnitzen. A or arch spread under imposed load. culation at platform level, the perimeter prominent fork-and-pin detail emphasizes the It will come as no surprise that snow load. at columns are spaced approximately 15m articulation at the suspension point. 1.6kPa, is high by UK standards. In spite of this, wind uplift - to which a tied arch is inherently vulnerable - called for greater design effort. Specialist wind engineering advice was taken on design pressures, based on analysis of local wind records and site topography, but, because of the similarity of the roof to previously studied shapes, no wind tunnel testing was considered neces­ sary. The conclusion was that the mass of the structure should be increased over the Zitronenschnitzen at each end where peak uplift pressures can apply, in order to main­ tain an ample factor of safety against reversal of load on the arch. A conservative approach was taken , partly because a decision had to be made before the final weight of glass was confirmed. The wall thickness of the main tubular arch members was increased to add the necessary mass: appearance remains identical to the others since the outside dia­ meter does not change. To the structural purist it may be slightly disconcerting to add mass in the form of steel, but only a few arches are affected and the onlooker need never know! One of the attractions of the Zitronenschnitz shape is that it lends itself to an elegantly curved end - on plan, as well as in ele­ vation. A variety of non-standard glass panes, triangular and trapezoidal, is not too much of a problem with untoughened glass which can be cut to size after laminating. Only one end of the initial phase has been 12 13 10. The north-east end. complete with column. 11 . The contractor opted for virtually all-welded construction. with good access from the bus deck under the greater part of this phase. 12. Various stages of assembly can be seen in this view, from the almost isolated zitronenschnitz unit on the right to the completed glazing at the end. 13. Construction under way at the temporary end. Escalators down to the railway platforms have yet to be installed. and the whole span is temporarily supported. 14. The bus deck: lingering snow creates the dapples on the roof. 15. The clusters of convex mirrors, and the spotlights which project onto them, are clearly seen in this view at the north-east end of the first phase. 16. The curved end of the roof seen from the bridge at the south-west end of the station. Buses enter under the building on the left.

6 14 15 given this treatment; the other is a straight go• Tubular structures look best if fully welded, Services end, destined to be converted into a move­ and for a structure on this scale that inevitably The lighting installation is unconventional and ment joint with the Phase 2 continuation over includes site welding. This particular nettle most impressive. It is another example of the railway tracks. was grasped at a very early stage in the international collaboration, involving the Aus­ To return to the columns, the substantial design process. However, it was regarded as trian consultancy of Prof. C. Bartenbach. bending moments at their feet (due to canti­ essential that all site welding should be rela­ Virtually all the illumination is indirect, origi­ lever action to resist lateral wind load) have tively straightforward - tube-to-tube butt nating from powerful spotlights mounted on obvious repercussions for foundation design. welds unimpeded by intersecting members the columns and reflected oH convex mirrors In fact, very substantial footings are required or simple fillet welds. An 'invisible' bolted in clusters, rather like grapes. at roof level. in any case, to resist stipulated impact loads detail, suitable for the purlins at their point of The effect which is desired, and achieved, is just above platform level (notional forces. contraflexure, was devised in order to avoid different from the uniform intensity of floor­ measured in MN, to represent derailed welding in difficult circumstances over the level illumination which many electrical engi­ trains). Consequently the penalty for canti­ tracks. It was foreseen that the complex neers would regard as their objective. levering the columns is not as severe as tubular intersections where the arches con­ The electrical risers and the downpipes from might be imagined. The majority of the Phase verge at the tip of the Zitronenschnitz, and the the gutters (stainless steel box sections with 1 columns are attached to the bus deck in slightly less complicated 45° junctions of the full-bore outlets) are enclosed within alu­ any case, and advantage is taken of this in columns. could most economically take the minium channel sections clipped to the the design. Future Phase 2 columns. which form of steel castings. Details were columns. Apart from a system of departure do cantilever from ground level, will require a developed on this assumption. In the event, indicators for the buses, and the clusters of small increase in diameter compared to those the successful tenderer preferred to fabricate mirrors, no services are suspended from the of Phase 1. the majority of these details by welding in the roof itself. Provision is made for an internal conventional way. Construction access system, but this will not be installed Working above an operational railway station. The fabrication contract was won, against until Phase 2; for the present, cleaning and with overhead electrification, makes the influ­ international competition, by a joint venture maintenance can be done from mobile equip­ ence of erection method on design more than led by Tuchschmid, a firm based in north­ ment operating on the bus deck. east Switzerland specializing in both steel usually critical. While a working platform, in Conclusion the shape of the bus deck, was available for structures and glazing systems. Several UK companies contributed as suppliers or sub­ Until recently, a project of this kind would, no most of Phase 1, th is will not be the case in doubt, have been viewed as an extravagance Phase 2. contractors. Erection of the roof took place during the summer of 1992. in a British city - we are accustomed to The strategy developed was for pairs of accepting a public realm which is visually Zitronenschnitzen to be preassembled over Phase 2, which will more than double the total and otherwise impoverished by comparison the working platform (which in Phase 2 will be length of the roof, is not due to be con­ with the private one, and nowhere more so a wide footbridge to be constructed across structed for a few years at least and may than on public transport. (Change trains at the middle of the station) and rolled or slid as have to wait for an upturn in the economic Leeds or Birmingham. say, or try to change a self-stable unit along temporary staging climate, to which Switzerland is not immune. between train and bus. to experience the down each column line. Only the minimum of While this description has concentrated on result.) But there are signs that this attitude is purlin connections had to be made at height. the roof, mention should be made of the bus changing. Perhaps the Chur project may Columns could then be lifted into place. or deck from which it springs. This is also a stand alongside its more glamorous counter­ restored to verticality, to allow the pinned steel-framed structure, treated in an architec­ parts at Waterloo, Lille and Roissy as an connection to the arch to be made. turally interesting way. example of what can be achieved.

16 Credits Lead client: PTT/RhB/SBB Architect: Richard Brosi/Robert Obrist Consulting engineers: E.Toscano AG/Hegland & Partner AG Sub-consultants for roof design: Ove Arup & Partners Alasta ir Hughes. Peter Rice. Mehrdad Bolourch,. Matthew Lovell Sub-consultants for glazing system: RFR Lighting sub-consultants: Bartenbach AG Illustrations: 1, 5. 11 -13: Photos: Tuchschmid AG 2: Courtesy Swiss Federal Railways 3, 4: Obrist und Partner 6: Robert Obrist 7-10, 14-16: Photos: Kurt Gahler

7 This paper is based upon a talk Mirror mirror on the wal I ... given to the former Old Centralians, the alumni of Imperial College, London, How fair is the engineer's image? on 13 May 1992. Sir Jack Zunz

Decline and fall? 'English culture and the decline of the indus­ examinations for the newly reformed civil ser­ You may recall that the wicked stepmother in trial spirit 1850-1980'1. Wiener's thesis is that vice were framed on the assumption that Snow White and the Seven Dwarfs consulted since the middle of the 19th century English, governing an industrial nation required her mirror frequently; yes, she was the fairest or more broadly British, culture has experi­ exactly the same kind of "liberally educated" of them all - except for Snow White. The self­ enced a profound polarization. On the one intellects as might otherwise seek a career in delusion that she was the most beautiful hand 'Englishness' has become identified the Church or even the university. Thus in the woman was cruelly exposed by the mirror. I with a pastoral image of a green and pleasant early 1850s was born the Whitehall mandarin, believe self-delusion to be an endemic and land, while on the other hand 'industrializa­ able at a touch to transmute life into paper debilitating ingredient of our professional tion' has come to be associated with dark and turn action into stone.· And thus the corri­ infrastructure; more of that later. satanic mills, ugly cities and general squalor. dors of power have since been manned by Newman's 'liberally educated' gentlemen. Britain's industrial decline is real and serious, He goes on to argue that the generations and has been going on far longer than most following the heroes of the Industrial Revo­ The image of the engineer is inextricably people are willing to admit. It is only compar­ lution were absorbed into the landed gentry interwoven with that of industry. The engineer atively recently that there has been general, if and that a revulsion against the less pleasant is the basic, the essential ingredient for a not total, realization of this home truth and aspects of industrialization and the adoption successful industrial society. Without the open discussion on how to halt and re~erse of the rural idyll as the desirable aspiration of engineer, civilization would not survive - we the decline has become more commonplace. modern life have resulted in more than a owe our health, our wealth, our means of The status and hence the image of the engi­ century of psychological and intellectual de­ transport, our shelter to engineers and engi­ neer are intimately interwoven with this indus­ industrialization. neering. That is not to say that other discip­ lines do not contribute to a civilized society. trial decline. Wiener's arguments, though flawed in some Statistics are often suspect, but if a series of detail, are substantially valid - and nothing But technology and its applications are both indicators all point in the same direction, per­ is more persuasive as to their validity than the the saviour and the potential threat to human­ haps one should sit up and take note. successive attempts to make appropriate ity. To use Cardinal Newman's terminology, Whether it is per capita GNP, percentage reforms to education and training in this 'liberal knowledge' may be a key constituent market share, currency strength, growth rate, country. of a civilized society, but without technology or any of the plethora of indicators dreamt up society will not survive, let alone prosper. So This peculiarly British disease of industrial for the sake of our continued wellbeing, let by an ever-increasing army of economists, decline is therefore not new. It is deeply they all present the same plain message and alone survival, a cadre of highly gifted, rooted in our society and, as Wiener says, educated and trained and committed engi­ it is stark. Our industrial performance is not goes back to the beginnings of the Industrial good enough. Successive governments have neers is a core requirement. The most able Revolution. For nearly 150 years individuals and talented young people must be attracted come to power with a variety of panaceas to and official bodies, men of vision and Royal cure Britain's ills - to little or no avail so far . into the profession. Can this be done? At Commissions, have attempted to convince present the signs are not promising. The 1992 General Election campaign and its public opinion and governments that the fundamental adversarial nature failed once When Samuel Smiles published his 'Lives of battle for export markets, for economic well­ 3 again to bring home to the public at large the being, was being lost in the schools and the engineers' in the mid-19th century the necessary disciplines and measures which in quadrangles of Britain. It comes as a surprise Prime Minister, Gladstone, wrote: 'It appears time might bring about a more productive to many that this debate has been going on to me that you have given practical expres­ and economically more successful society. for as long as it has. Cardinal Newman, one sion to a weighty truth - namely, that the The populist exhortation to be part of the of the most influential men in education in character of our engineers is a most signal 'enterprise culture' is not enough. To be Victorian times, apparently thought all 'useful' and marked expression of British character . . enterprising, to go out and establish new ven­ knowledge to be trash - he was more inter­ .' 19th century British engineers appeared to tures and businesses is all very laudable ested in the cultivated gentleman and provid­ be heroic figures - symbols of a great age, when there are appropriate skills to back up ing him with a so-called 'liberal' education. much like the sea captains of Elizabethan times. Even today, many members of the the enterprise. But so much of this much­ Why liberal and scientific/technological edu­ vaunted 'enterprise culture' is built on froth pub_lic have heard of Brunel and his singular cations should be mutually exclusive I shall achievements, of Stephenson's locomotive, and it is beginning to show. Simplistically, never know, but it is a theme which for a wealth is created by one of, or a combination and Watt's steam engine; Stephenson and number of reasons has become deeply en­ Faraday are even displayed on our bank­ from , three processes - growing things, min­ trenched in the culture, in the education sys­ ing things, or most important of all, making notes. But the museum in which Watt's tem. and indeed in the minds of the people of engine is displayed is called the Science things. Other economic activity pushes this this country. basic wealth around. Service industries are Museum, even though most of the displays becoming ever more sophisticated, but they Correlli Barnett in his excellent, somewhat when I last looked at them were of an engi­ need something to serve. Major service frightening, and salutary book 'The audit of neering nature - so why is it not called the industries - banking, insurance, advertising, war'2, articulates only too well why succes­ 'Museum of Engineering' or at least the telecommunications, entertainment, leisure, sive governments, spurred on by commis­ 'Museum of Science and Engineering'? What retailing, distribution, transport, travel and so sions of inquiry and other official bodies, have went wrong? on - ultimately depend for their existence on failed to take the advice given them and to More than 100 years after Gladstone, our cur­ the three wealth-making processes, both for heed repeated warnings on the conse­ rent Prime Minister John Major said (some their paying customers as well as for their quences of the lack of appropriate education five months before the Election): ·.. . and that equipment and machinery. in general, and technical education in partic­ places a special premium on the skills of ular. Barnett writes: 'The exponents of what those who can make things happen, those In that context an enterprise culture, based Newman called "liberal knowledge", i.e. who can apply scientific knowledge, those on wealth creation, can only flourish if it is knowledge unrelated to what is "particular who can make sure that scientific knowledge underpinned by a large cadre of broadly­ and practical" and enshrined in such discip­ uses nature's resources to benefit mankind. trained and educated professional engineers. lines as the classics or mathematics, won a And that in the wider application is what engi­ Without this foundation, the enterprise culture particular success which was to determine neering is about and it is because of what will remain a castle in the air. the character of the British state bureaucracy engineers have done and the fruits of their The American historian Martin J. Wiener pub­ for the next century. For, thanks largely to a work that these days we live healthier lives, lished a book about 10 years ago called coterie of Oxbridge alumni, the entrance longer lives, in many ways more comfortable

1. The epitome of heroic Victorian engineering: the Forth Rail Bridge, completed in 1889. (Illustration: Simon Miller, from the forthcoming book 'Bridges', courtesy of Mitchell Beazley Publishers.)

8 2. Engineering can be as visionary and challenging today as in the 19th century: Collage of La Defense. Paris, showing planned location of the 426m Tour Sans Fins, the slenderest tall ottice building in the world. Architect: Jean Nouvel; structural engineer: Ove Arup & Partners. (Photo: Georges Fessy)

lives than previous generations. Maybe politi­ nition of engineers in contemporary Britain. brightest and the best. In the same survey the cians occasionally take the credit for it but the The one referred to a social verdict, whereas rating of industry, in terms of interest and sta­ reality is that it is the innovation and brilliance the other to a social need. This can only be tus, was near the bottom of the students' per­ of men and women who have been engineers achieved by a cultural shift. The image of the ception. Doctors, accountants and lawyers who have actually brought about so many mid-19th century engineer was clear, and were at the top in perceived status, interest changes .. .'; and again: 'In years gone past, heroic; the image of the engineer today is, to and pay. over generations, I feel we have been less say the least. obscure. The engineer today is an enigmatic, myster­ good than some of our main competitors at What then is the image of ious figure whose perceived skills vary from getting enough of the best young people into the engineer today? being able to tighten bolts to repairing broken engineering. And the reason for that is one I In 1990 Gallup carried out a survey for the water mains. Our environment is generally feel deeply about myself and have touched CBI to establish attitudes of 17 and 18-year­ perceived as being the creation of architects, upon on many occasions. It is that instinct olds intending to enter higher education planners, surveyors and builders, while our embedded deep in our culture that previously establishments. It indicated that 5% aimed to industry is under the control of managers who tended to disdain industry and give more study engineering; about 8% were pursuing a employ workmen of varying skills, including kudos to classical education than to techno­ career in 'Research, design or development of course technicians and last and usually logical education.' including engineering' - a composite head­ least. designers. This deliberately rather cari­ Rather poignantly, there is a significant differ­ ing which only pollsters totally ignorant of the cature-like picture is to make the point that ence between Gladstone's sentiments and needs of industry and the country would the engineering world is lost in a kind of Major's. Gladstone spoke with admiration of dream up. But the trend is clear and the fig­ semantic and conceptual miasma. The image the perceived standing of the engineer at that ures don't indicate the quality of the students of the engineer, the professional engineer. mid-19th century time, whereas John Major attracted to engineering; there are strong has become lost in the mists of time - that expresses a need for approbation, for recog- indications that on average they are not the time being the latter part of the 19th century.

9 3. Principal navigation span for the Oresund Link between Sweden and Denmark, in the shortlisted design proposed by the ASO Group, led by Ove Arup & Partners. The pylons are 200m high and the span 490m; the double deck, rare for a cable-stayed bridge. is designed to carry a roadway above and rail below.

What then is to be done? geoning management consultants industry lines'. One would expect that great Depart­ The first thing is to stop whingeing. I have no which feeds on the incompetence of the ments of state like Transport, Environment. patience with those who complain about our industry it purports to serve. A manager can not to mention Trade and Industry, would lack of status - we get the status we manage anything from a mail order business have many engineers at the most senior deserve. We the engineers must go out and to an aerospace industry, or so the conven­ levels. There are very few. The private sector do something about it. There is unquestion­ tional wisdom goes. But anyone who under­ is even more deficient in engineering leader­ ably a vicious circle which has to be broken stands even the basic elements of leadership ship. It is salutary to examine the boards of and turned into a benign circle. The vicious (and I use this word advisedly - not 'man­ the leading technical companies in this coun­ circle goes something like - low rating in agement') knows that in general, leaders will try and compare the directors' qualifications image and status, low appeal to talented only win the support and respect of the led by with that of their peers in Germany, France. young men and women, low expectations, example and performance. And this respect Japan and so on . low hierarchical achievement and so back to is most readily gained by a feeling of identity. It is too much to expect effective change in status and image. which can only be achieved when the leaders our secondary education system, in the short It is as well to pause here for a moment. At are steeped in the industry they purport to term anyway. The government's thinking is the first United Kingdom Engineering Lec­ lead. The oft-repeated proposition that engi­ still inspired by the selfsame mandarins who ture, given at the Royal Society in February neers make poor managers and captains of consider A-levels to be the gold standard of 1992 by Akio Morita, the Chairman of the industry is nonsense - and is often made by the English education system. Maybe some­ Sony Corporation, he said inter alia: 'In those who have a vested interest in protect­ one will tell them that the rest of the world has Japan. you will notice that almost every major ing their position. It is true that not all engi­ gone off the gold standard. but in the mean­ manufacturer is run by an engineer or tech­ neers make good managers, but then not all time we have to make do with what we have. nologist. However, here in the UK I am told engineers are good designers. Nor are all And this is where the engineering institutions some manufacturers are led by chief execu­ doctors good diagnosticians. An engineering could take some initiatives. tive otticers who do not understand the engi­ (or more generally an industrial) enterprise needs leaders with a variety of strengths and Snow White's stepmother was flirting with neering that goes into some of their own self-delusion. I am afraid that the engineering products. Someone once mentioned to me talents. What is pertinent is the depth and width of education which engineers in this establishment in this country has been doing that many UK corporations are headed by just that for many years. The fragmentation of chartered accountants. This strikes me as country receive to enable them to aspire to leading roles in industry, so as to make it the profession does not help. Buchanan's very curious .. .' 4 more successful against foreign competition. book 'The engineers' is an interesting And so it should, for it is a kind of madness Education of engineers is relevant not only to account of the development of the engineer­ which has overwhelmed industry in this coun­ industry but also in manning the corridors of ing professions in Britain from 1750 to post­ try, and can only be properly articulated by a power in government. World War 1, and graphically relates how the foreigner who can look at us dispassionately It is a difficult issue. The 'two culture syn­ profession has split into its sub-tribes, to the and clearly. In our lawyer/accountant-domi­ drome' is deeply embedded in the system. I detriment of its standing with the public. nated economy, technology is something to believe that in order to break into the vicious The number of institutions representing the be bought, like groceries at a supermarket. circle more engineers have to be visible role engineering sub-disciplines is a major factor Engineers are not thought to be proper per­ models for young people to emulate. not just in professional engineering not being effec­ sons to head enterprises because their for the status and monetary rewards they tively presented to the public and to govern­ education, their training, and hence their out­ might (and should) attract but also and, more ment. with a consequent diminished influence look and performance. are thought to be too importantly, for what they contribute to the and status. The Engineering Council has little narrow and inadequate. wellbeing of society. I quoted earlier Correlli real power and the vested interests of the Add to this the cult of the professional man­ Barnett's reference to the Whitehall mandarin individual institutions prevent it from present­ ager which has become the vogue in the past whose education was expected to follow ing a common front as do other professions. 15 years or so. This is propped by the bur- what could broadly be termed 'Classical The current efforts of Sir John Fairclough to 10 4. Concorde (Photo: courtesy of British Airways)

images - if they require some fabrication that's alright provided the paying customers are satisfied. And so everyone knows that the Lloyd 's building in London was built by Richard Rogers, and that (for those old enough to remember) the Festival of Britain Skylon in 1951 was designed by Powell and Moya. I am a great admirer of Utzon, of Rogers, and of Powell and Moya, and have on many occasions waxed lyrical about their talents. But to imply that they individually created these artifacts is like suggesting that Botham won the Ashes single-handed. I once tried to find out who designed Concorde, surely one of this century's most impressive ikons. It is near impossible - the creation of Concorde was apparently the result of a n~mber of developments with many con­ tributors, some more seminal than others. To raise the image of the engineer in the public's eye we have to strike a fairer balance between obsequious anonymity on the one hand. which is the general case at present, and unfair exploitation of the cult of persona­ lity and the 'I did it all' syndrome on the other. This is not easy, but with some imagination it can be done. This brings me to my second point concern­ ing the media. Television is unquestionably the most powerful communicating medium. The key rOle of the professional engineer is seldom if ever seen in documentaries, nor is it generally featured in light or serious drama. ROie models of lawyers or doctors are regular features in television soaps, and artists or architects regular subjects of documentaries. While we as a breed may not be as exciting bring about a more united profession deserve in industry and government came up. At the as Perry Mason or Dr. Kildare, what we do is wholehearted support. But it is one of those same time the challenge of becoming a pro­ often quite breathtaking. The story of some of situations where most of us agree in principle fessional engineer might lure more and the century's great engineering achieve­ that something needs to be done, but some­ brighter young men and women into the ments, some of which the public now take for how there is institutional inertia to be over­ profession. It could be one way of breaking granted, are exciting tales and in the hands of come. Why we can't have a Royal Institution the vicious and creating a benign circle - i(!1a~inative_ producers could make good of Engineers speaking on behalf of all profes­ rOle models would appear for others to follow. v1ew1ng . This may be thought superficial , but sional engineers seems odd to me , but one The institutions are really central to changing 11 does matter if we want to attract young must hope Fairclough's efforts will take root. the engineer's image. Self-delusion, the idea people into the profession. The young, their The image of professional engineers would that all that is British is best by definition, has talents and commitments are central to en­ be immensely enhanced ii a respected cen- for too long played a part in institutional think­ hancing the standing of the engineer, and 1ral body was able to speak, and on certain ing. The maintenance of the status quo has television and of course other mass media issues to act, on their behalf. This is parti­ been paramount - all very understandable are powerful means whereby the young can cularly i~portant in this age or media power. when it is viewed as a residue of the Imperial be influenced. Again the institutions, particu­ when 11 ,s important to have simple concepts hangover, mixed with a generous measure of larly if their resources can be pooled, can which can be easily communicated and post-Victorian pomp. But there are signs of play a. centr~I role in introducing engineering understood. hope. In some institutions there is undoubt­ ,n a st1mulat1ng manner to the media. edly a wind of change. But the most important But the institutions in their present guise as To sum up then , our image is not as fair as it learned societies have a more important factor in the first place is for us a// to agree !hat there is a severe problem in our public could or should be. The industrial wellbeing immediate role . I said that secondary educa­ of this country is inextricably interwoven with tion will not change overnight to give our most image and that collective action with perhaps some personal and corporate sacrifice may our image because only with a fair image will talented young men and women a funda­ talented young men and women be attracted mentally broader educational base. It will be necessary to bring about change. We must rid ourselves of any residual self-delu­ to engineering. We must not complain: the come in time - maybe influenced by in­ solution is in our own hands. Putting our creasingly common European standards, or sion, our performance must be improved and must be seen to be improved before our house in order will go a long way to enhan­ by the example of others. In the short term the cing our image, as will broader educational institutions can by their entry requirements image and hence our status are enhanced in our society. requirements and greater public exposure. It gradually introduce those skills which most will take a long time and while looking into the young engineering graduates now lack. That brings me to the question of our relations with the public at large. Communications mirror is not all bad news, we should not Proficiency in languages including English , physical and non-physical, are probably th~ delude ourselves that all is rosy in the garden history - at least an historical understanding most significant accelerators for change in - it is not. But it is up to us to get out there of the context of their chosen profession this century. As a consequence, the power of and do something about it. No-one else will. - skills in communication: these are but a the media is a fact of life: we have to live with References few examples of the kinds of subjects which it, like it or not. I will touch on just two aspects (1) WIENER, M.J. English culture and the decline of coul~ be introduced gradually into the entry of the media which affect our image. Sydney the industrial spirit. 1850-1980. Penguin, 1985. requirement. Opera House was designed by J0m Utzon. or (2) BARNETI. C. The audit of war. This could have some interesting conse­ so the guide who conducts thousands of Macmillan. 1986. quences. First and most important, young visitors to the complex will have you believe. (3) SMILES, S. Lives of the engineers. chartered professional engineers would be No-one else is mentioned in the hour-long John Murray, 3 vols. 1862; 5 vols 1874 (revised). educated and trained to the same standards tour. The fact that what is now standing in Selections, The MIT Press. 1966. as many of their foreign counterparts. Their Sydney Harbour was built without a single (4) BUCHANAN, A.A. The engineers: consequent self-esteem would make it im­ drawing or instruction from Utzon is beside history of the engineering profession in Britain possible for them to be ignored when top jobs the point. Our society likes its instant pop 1750-1914. Kingsley, 1989. 11 sal beam (US) grade 50 steel with the top flange removed to form the profile). River Aire The short vertical members of the vierendeel girder were also formed from 400 x 200 x Footbridge 16mm RHSs. The 8mm thick grade 50 deck plate is stiff­ Colin Harris ened by 100 x 100 x 8mm rolled steel angle (RSA) members running between transverse Mark Steele members and parallel to the centreline of the deck. A curved 8mm cover plate is provided Introduction on the outside of each vierendeel girder to The River Aire Footbridge is the first river give a clear drainage path for deck surface crossing to be built in Leeds for more than water away from the vierendeel girder, as well 100 years . It is sited in the oldest part of the as clean simple detailing for the external City, separated from the Parish Church by elevations. The adoption of twin vierendeel The Calls, a road linking Leeds Bridge and girders with the deck spanning between Crown Point Bridge, both of which also span enabled a simple boss cable connection the River Aire. fabricated from a stiffened circular tube In 1988 Leeds Development Corporation and a stiffened fabricated connection to (LDC) carried out a study to identify the 400 x 200mm RHS members. strategic connections between the City and A concrete mast was appropriate. bearing in the South Leeds Urban Regeneration Area. A mind the largely compressive forces and the vital pedestrian link was identified from the sculpted cross-section. The selection of ten­ Corn Exchange through to The Calls across sion stainless steel wire parapet between the Aire to link with the south side and the vertical posts cut from 203 x 133 x 30mm Clarence Dock basin in particular - a site UBs, and timber handrails, was in response since identified for the Armouries Museum. In to the slender deck profile and the nautical May 1989 Ove Arup & Partners were 2. Lifting the deck, 10 June 1992. aesthetic. Conventional pedestrian parapets appointed by LDC to carry out a preliminary would detract from the slender appearance, appraisal for the pedestrian bridge. particularly from a distance. The stainless The ground conditions comprise alluvial steel wires pass through the parapet uprights sands and gravels, overlain by made ground and are isolated by nylon grommets at each associated with warehouse development location. along the banks of the River. The underlying All these constraints led to a study of through­ Construction bedrock contains lower coal measures of the girder, suspension and cable-stayed solu­ The foundations comprise 230mm diameter carboniferous age: mudstones, sandstones, tions. mini-piles founded in sandstone. During siltstones and coal seams. The Black Bed The asymmetry of the warehouse buildings construction the piles beneath the south abut­ coal seam is present close to rockhead but on the north bank and open space on the menVkentledge block supported its self­ no evidence of shallow mineworking was south bank suited a single mast, cable­ weight until the dead load reaction from the established at the abutment sites. stayed solution. A through girder using the backspan cables relieved some of this load. Constraints girders as parapets would have been reason­ In extreme flood conditions an increased The geometric constraints of the site defined ably efficient but of solid appearance. and it factor of safety is provided by the same piles a very narrow envelope in which to fit the was also considered that attempts to repli­ acting in tension. bridge structure. The relatively short cate the tracery of the adjacent Victorian A Department of Transport paint specification approach possible on the north bank from bridges would be contrived. The single mast was selected for the steelwork, comprising The Calls to the River edge, combined with a solution was selected and further studies blast clean, metal spray sealer. and MIO/chlo­ maximum gradient, defined the upper bound undertaken to optimize the design. rinated rubber undercoats and finish . A total of this envelope, whilst the requirement for a dry film thickness of 200 microns was navigation clearance to match that of the The solution Following sketch schemes with varying num­ achieved. The deck footway surface is a two­ adjacent Crown Point Bridge, together with bers of cables, different inclinations of the component coal tar epoxy manufactured by flood clearance at the river edges, dictated mast and parapet types, the final built form Cicol. All exposed concrete finishes including its lower limits. A further requirement, that was selected . The design intent was to the mast were treated with anti-graffiti paint. there should be no support within the River, necessitated a structural form with a relatively achieve simple uncluttered detailing, possibly The deck steelwork was fabricated by reflecting the nautical flavour of masts and thin deck supported largely above soffit level. Billington Structures and delivered to site in cables in such important elements as para­ three sections, welded together on temporary 1. Location plan. pets and handrailings. staging to achieve the correct profile prior to During the scheme studies the advantages of erection. The white concrete mast was combining the principal structural elements precast by C.V.Buchan and delivered to site as part of the parapet were recognized, par­ as one complete unit. The contractor elected ticularly as a relatively thin deck could be to erect the deck and mast in one operation achieved. Studies of main members span­ using 500-tonne and 200-tonne capacity ning between cables led to the selection of mobile cranes from the south bank. In a 12- vierendeel girders. The top boom (400 x 200 hour operation in June 1992, the mast was x 16mm rolled hollow sections (RHS) in grade lifted vertically, the steel deck threaded 50 steel) forms the lower part of the parapet, through, and the two components lowered whilst the bottom boom (250 x 150 x 16mm onto the permanent bearings. Three months RHS in grade 50 steel) forms the support to later the project was completed with the land­ transverse beams (205 x 102 x 25mm univer- scaping and approach works.

3. Elevations.

E M '°

,, I,: " ,, . II 11 u IJ '1 South approach 11 .Sm 433m

12 4. Underside of the deck. showing transverse and longitudinal stittening.

5. The bridge viewed from the east.

7. The bridge at dusk from the north bank. In the background is the Tetley 'Museum of Pubs' (building and civil engineers: Ove Arup & Partners Leeds).

Credits Client: Leeds Development Corporation Structural engineers: Ove Arup & Partners Leeds Cohn Harns. Mark Steele, Gillian Blake, Adam Crewe, Peter Chamley Main contractor: Kier North-East Ltd Illustrations: 1 Martin Hall; 3: Steve Capper Photos: 2: Chris Shaw Photography; 4-7: Paul White Photography

North approach

13 Introduction and trip working needed for rail The history of Weardale, the upper movement was no longer viable. valley of the River Wear in County A short-term change of decision was Durham, is closely connected to that therefore extremely unlikely. For the of the Industrial Revolution, and long term. consideration was given to particularly the railways' role in that the possible impacts of privatization, Revolution. and the changes in grant support In the lower dale there has been coal currently proposed by government to mining since the 14th century. By the encourage diversion of freight traffic 18th century the demand, particularly from road to rail. An illustrative from London, meant that means were example was developed to indicate sought to connect the South Durham whether a private freight operator coalfield to Teesside. Alter a canal might find rail haulage financially proposal failed , it was the Stockton attractive. and Darlington Railway which Based on previous research by provided the outlet to the sea in 1825. Witton Park was the western terminus Arups, assumptions were made about of the line. average carrying distance. road and rail haulage costs, and depot In the upper dale, limestone, iron ore charges. Application of the proposed and lead mining companies were the grants was estimated to reduce rail major employers by the 19th century. costs below road haulage costs at Opposition from local landowners and about 300 OOO tonnes per annum. the high expenditure involved meant Reversal of the decision would, that a rail connection to Stanhope was however, require assured movement not achieved until 1862 and to of about 400 OOO tonnes - equivalent Wearhead only in 1892, by which to the previous maximum rail usage at date the mining boom was over. peak production. Weardale is now predominantly an Darlington to Bishop Auckland agricultural area, with few signs of Information from BR Regional past industry. The upper dale is now Railways was used to assess the part of an Area of Outstanding Natural existing financial performance of the Beauty and the lower dale an Area of line from Darlington to Bishop County Landscape Value. The towns Auckland - it was broadly average and villages are also of high visual for regional railway services. Since quality and are protected by the freight usage by Blue Circle only Conservation Area status. covered the marginal costs incurred The de-industrialization which began there would seem to be no immediate in the 1890s meant that the Weardale threat to this section of the line. Railway never carried the amount of However, future opportunities for traffic forecast prior to construction. further traffic were examined: The passenger service from Bishop (1) Improvement of the existing Auckland was withdrawn in 1953, and passenger service by introducing a by the 1970s the only freight use was regular hourly service was found to related to the cement works at be practical and cost-effective. With Eastgate. In 1992 Blue Circle an increase of only £50 OOO on top of reassessed its national distribution the renewal/upgrading costs needed system in the context of long-term 1 Steam locomotive at Shildon Tunnel , 28 March 1993. in any case to maintain the present decline in the cement market. and the service, an increase in net revenue of increasing costs of rail usage. about £170 OOO p.a. was forecast. Transfer of freight from the Weardale The study also suggested that an line was announced to take effect in additional station could be worth pur­ April 1993. suing in terms of revenue increases. The brief Rookhope I \ (2) The opportunity for development The local authorities in the area led by K, Wheel ., • Dales Cer'ltre • Tuns1a 11 Reservotr of a freight depot at Faverdale (north Durham County Council together with St of Darlington) had been the subject of the Countryside Commission, and Eastgat a previous study, but without supported by a large number of local consideration given to the economic groups, sought an independent study case. Comparisons were made to assess, prior to the closure of the AREA OF OUTSTANDING NATURAL BEAUTY between road and rail haulage costs. line: suggesting that there could be a (1) whether there was any possibility promising role for private sidings or a of Blue Circle reverting to rail use in Key specialist terminal geared to wagon the short or long term t3 E,c,st,ng attractions load traffic, to and from long-haul (2) what effect the withdrawal of • ~xact,ons/ destinations in central and southern freight might have on the remaining Area et Outstan

14 3. Newlandside West Quarry, Stanhope.

4. Level crossing and former station building, Wilton-le-Wear. 5. River Wear, Durham Wildlife Trust Nature Reserve, Wilton-le-Wear.

The low population in the Dale to judge how far the Weardale Line Conclusions Credits meant that an annual revenue of could offer an attractive alternative to The steam railway was the one Clients: under £100 OOO could be expected. visitors. The main conclusions were initiative which could be directly Durham County Council, Wear Valley District Council, With regard to waste disposal, the that: influenced by the client bodies, and enable retention of the line in the Sedgefield District Council, opportunity for connection to the • The railway would need to rely on Darlington Borough Council, railway at Heighington Lane waste tourist visitors holidaying in the area timescale required. It was therefore Countryside Commission. transfer station and at Stanhope for the majority of its income and recommended that the client Consultants: quarries had both been maintained . would be competing with the North undertake a business plan for the Ove Arup & Partners Newcastle Office The study indicated that rail had a Yorkshire Moors Railway for such steam railway and that BR be asked Mike Brown. Ray Noble cost advantage over road haulage custom. to postpone a decision on the re-use Arup Economics and Planning only if over 500 OOO tonnes p.a. were of the redundant track, to enable Mark Bostock. Adrian Gurney. Andrew Marsay • Its direct accessibility from the East transported over distances greater progress to be made. Arup Transportation Coast Main Line and the A1 and A68 Ed Htxnphreys, Ben St oll than 80km. This would only be likely if corridors, plus the range of current With regard to the other possible Arup Highways large quantities of waste from and proposed visitor attractions, initiatives, BR expressed particular Rocllatd Foster surrounding counties were to be would provide some significant interest in the possibilities of Illustration: available, indicating the need for a advantages. improvements to the passenger 2: Jon Carver major shift in comparative costs of service between Darlington and Photos: incineration and disposal. • The area's connection to the Bishop Auckland. As to freight and 1: North News and Pictures: Steam railway railway heritage of the early Industrial waste disposal, long-term 3-5: Adrian Gurney A summer Sunday service into Revolution provided a strong focus for opportunities suggested that development of the line. Weardale has been supported by the continued safeguarding measures local authorities since 1988, and • A strategy would need to be were likely to be appropriate. various studies have suggested that developed which concentrated on The report was prepared within a very development of a steam railway could integrating appropriate attractions, short timescale and the client has form a key feature of a tourism and marketing the railway at expressed considerable appreciation strategy for the area. associated tourist locations in the of its usefulness. In view of the current The Arup study looked at previous region. changes on the railways it is likely that work and assessed whether the • There were several key conditions similar studies will be requested in the proposal was worth pursuing further. for the success of the venture which future, and Arups are building up a Comparisons were made with other would need to have realistic significant body of experience to steam railway ventures in the region commercial objectives. assist in such work.

15 Original building design shear reinforcement. Additional shear link re­ Reinforced concrete was not recognized by inforcement was rare. St. George's House, the Manchester by-laws in 1908, so the city Each floor is covered by a structural screed Manchester authorities involved themselves closely in the to achieve composite and diaphragm action. design and indeed the basic design criteria. Stability was secured by a combination of For example, the engineer proposed that framing action together with vierendeel effect each floor carry a superimposed load of of the stout external terracotta-clad fai;:ades . Geoff Bickerton 8kN/m2, but the local authority insisted upon 11 kN/m2 - over four times the current British In areas which required large spans such as Steve Burrows Standard recommended loading for offices over the auditorium (Fig . 6), full storey-height (2.5kN/m2). The city also required prototype walls acted as beams carrying two floors. A Mark Elsegood testing to destruction of concrete elements to large opening at mid-span formed the corri­ prove the design assumptions. dor between cells.formed by the wall beams. Concrete portal frames were used at roof Introduction The original designers, however, still man­ In 1908 the Young Mens Christian Asso­ level to span over the running track (Fig . 5) , aged to incorporate many unusual features which was suspended by reinforced concrete ciation (YMCA) identified a brief for a prime with the new material. Even the 9m high flag ­ 11oom2 Manchester city centre site (Fig . 2) , hangers. The concrete was hand-compacted pole was in reinforced concrete. though the with timber poles. adjacent to the Midland Hotel and the Central original designer noted that during a stiff Public Library. The proposal included a cafe, breeze 'the pole whipped about like a piece The only area in which the designers' confi­ billiard room, kitchen, shops, offices, two of lance wood, moving about four inches out dence in reinforced concrete appears to have auditoria seating 1OOO and 160 respectively, of the perpendicular in each direction'. wavered was beneath the fifth floor level classrooms and lecture theatres, a swimming swimming pool (Fig . 4), where steel plate pool, gymnasium, running track and two fives Interesting construction techniques were also rivetted trusses encased in concrete carry the courts. used , including erecting the elements of the considerable loads to the reinforced concrete terracotta fai;:ade adjacent to a single-sided columns. It is important to recognize the The planning height limit of 30m on the timber former and then filling the void with fai;:ade set the overall criteria, and deter­ pioneering nature of the original designers concrete using the terracotta as permanent and the significant learning curve which the mined the need for eight levels including a formwork. basement. A design was developed based builders went through during construction. on a masonry-clad steel frame, and was put The principle structure is of square reinforced However, the deficiencies of the time were out to design-and-build tender. Five contrac­ concrete columns, with hooped reinforce­ also abundantly evident in lack of com­ tors bid on the basis of a performance speci­ ment cages supporting reinforced concrete paction, large tolerances, and initial setting­ fication and each was asked to produce a beams. These carry reinforced concrete ribs out errors. Despite this, the building fulfilled designed response and a construction pro­ with hollow terracotta infill blocks known as its purpose for 80 years: testimony to the gramme. Four of the returned tenders were the Kahn floor system, a peculiarity of which robustness of reinforced concrete. deemed to have met the brief, and the con­ was the use of bent up steel wings attached Investigation tract was awarded to the second lowest to the rebar which supposedly acted as In early 1990 Arups were appointed by Man­ tenderer, J.Bentley & Co. of Bradford. They chester and Northern Developments Ltd ., on were chosen because of their unique re­ behalf of Eagle Star, as structural engineers sponse: they had designed the building with for the refurbishment of the building. The the swimming pool at fifth floor level and the structure was listed both internally and exter­ running track suspended from the roof. The nally as Grade II by English Heritage, which large auditorium was on the first floor, meant that a relatively simple fai;:ade reten­ occupying two storeys on the north side of tion refurbishment was not possible as mini- the building. No tanking or waterproofing was proposed to either the roof or basement and New canopy the structural frame was to be formed using a new material - reinforced concrete. The Seve nth 3.5m tender sum was £35 OOO.

The building (Fig. 1) was completed in 16!h s, xth 35m months and proved a tribute to the skill and ~ ~ / ~ confidence of the designers - The Trussed 2. Location plan. () -~ Origin~~ Fi hh 3 .Sm Concrete Steel Company Ltd of Detroit, USA, fives courts who paid for the design to be checked by a I/ 2.0m f' I Orioinal rt nnino track I I British Chartered Engineer as requested - (Ii 5) 2.3m - LJ L Four th 5 .2m under the terms of the contract. Original "' n pool (fig 4) r Origin !gym 31m I I 3. East-west cross­ Thi rd 30m section showing the 3.4m New relationship between planar original structure and glazed Second 4 7m new-build. 31m canopy p Original auditorium c::::::::: FirSt 36m 45m (fig 6)

grou nd 5.2m Key 36m New atrium Original structure retained , Basement New structure

Original structure removed Sub-basement

1. The building as originally completed in 1909. -- J f' 86m 81m 45m 7m 45m i,

16 mum demolition of the structure itself was geology in this part of Manchester and no Sequence and method required by the listing. It was thus important problems in this regard were anticipated for of construction to understand fully the limitations of the exist­ the new building design. The requirement to retain substantial areas of ing building in order to design the refurbish­ Due to the need to carry out a soft strip of fin­ the existing floor and all the far;;ades im­ ment. The structure's unique nature and its ishes and then to open up areas of the build­ pacted on the sequencing of demolition, tem­ specification caused much interest in 1909 ing for more detailed investigation, it was porary works and reconstruction operations. and generated a number of technical articles decided that this work was best done once The temporary works included the following which revealed the theoretical design basis the contractor was appointed. Consequently, key items: for the building. However, only limited 'as a tender was prepared and a contractor • propping the two-storey high basement built' drawings existed, and because of the appointed. retaining wall to an adjacent building pioneering nature of the job, some on-site modifications were expected. Original linen The investigation work in the early stages of • propping the unsupported edge of architects' drawings were held by the City the construction programme had three aims: five storeys of retained floors at the rear Archivist and this information formed the • supplementation of the initial investigation of the building basis for a visual appraisal of the building's following the removal of finishes • installing temporary stability bracing performance over its first 80 years. • dimensional checking of the to these retained floors Various adaptations had occurred over the as-built structure • far;;ade retention for half of the elevations. years , the most significant being the sub-divi­ • co-ordination of the temporary works The contractor developed a complex and sion of the large auditorium, horizontally and support with the new design. inter-related construction sequence involving vertically, to provide extra accommodation simultaneous demolition, propping, and re­ during World War 2. The flagpole had also This latter requirement was a key part of the construction works, as it was vital to under­ construction within the confines of the re­ disappeared although it is not clear whether tained far;;ade and floors. This was continually this was planned! Generally, the structure stand fully the constraints the building im­ posed on the construction sequence and use re-evaluated and re-scheduled as construc­ was found to be in reasonable condition, tion progressed. although the presence of finishes limited the this, together with the contractor's buildability scope of the initial investigation. expertise, to co-ordinate demolition and re­ Before any internal demolition had taken construction. This phase of the investigation place, a vertical cantilever scaffold far;;ade The primary visible defects centred around proved the variability of the frame construc­ retention system was constructed on Mount the consequences of the level of workman­ tion and emphasized the complexity of the Street and part of Peter Street, anchored into ship, as well as poor detailing of sensitive task that lay ahead. existing columns at basement level and into a areas such as the swimming pool. This had The rib sections of the beam and pot floor ground beam on mini-piles in the external obviously leaked for a long time, and there pavement. was much evidence of attempted repairs. The were notably poor, due to lack of initial com­ consequent reinforcement corrosion was a paction of the heavily reinforced small sec­ The rear basement wall propping system and particular feature throughout the structure. tions. It was also clear that the quality of work­ the five-storey high floor propping and stabi­ manship improved as the builder became lity bracing were both erected whilst demoli­ The next stage of the investigation involved a more familiar with placing reinforced con­ tion was under way. The basement wall was physical examination and testing programme crete; thus the higher level concrete was supported laterally by using vertical channels to establish the residual strength and vari ­ quite good but the lower levels were honey­ anchored through the wall with high strength ability of the originally specified concrete combed and poor. Unfortunately for the tie rods grouted into the sandstone bedrock strength of 16N/mm2. From test cores taken , columns this is the opposite to the loading under the adjacent building. This provided a a design strength of 11N/mm2 was deter­ pattern, so while structural investigation sug­ clear working space within the building for mined by statistical analysis although values gested that the floor plates were adequate for subsequent demolition and reconstruction. as low as 8N/mm2 were recorded. Modern the new use, the columns were deemed in­ Floor supports and stability bracing were pro­ standards require 35N/mm2 for durability, so adequate, especially at the lower levels. vided by a system of soldier beams braced this deficiency needed to be addressed. with scaffolding. Chemical testing revealed that no chlorides Architectural design concept were used in the original mix but carbonation Central Manchester's office stock is not New construction and repair or strengthening depths up to 100mm were recorded. Cover to generally of high quality in terms of spacial of the retained structural elements began as reinforcement was variable: some areas had and environmental performance. St George's soon as areas were clear and safe from adja­ over 1OOmm while elsewhere the reinforce­ House was to be an exception: high quality, cent demolition operations. ment was exposed. well-integrated, visually interesting, and with Structural design a high performance HVAC system. The nature Any proposal to retain parts of an original A geotechnical desk study of the site sug­ of the existing building, with its variable gested that the foundations would be on structure and insert new elements elsewhere volumes and differential levels, generated naturally leads to a variety of design solu­ Bunter Sandstone immediately below the difficulties but also opportunities to achieve sub-basement slab. This is typical of the tions. Finding the most appropriate solution these ideals. inevitably revolves around the flexibility of the The circulation concept provides a pedes­ design and its ease of integration into vari­ trian entrance to the office accommodation able and often unknown situations. off Peter Street at the centre of the primary This requirement for flexibility tended to frontage, naturally sub-dividing the ground favour a design based on reinforced concrete floor into two retail units. A car park below the as the predominant material. However, the ground floor level has access off Mount Street complex sequence of temporary support, to serve both office and retail users. The retail demolition, and reconstruction would have accommodation is accessed from the street been further complicated by the formwork level on the primary frontage. and falsework needed for reinforced con­ Above ground floor, rationalization of floor crete, so the choice fell on a steel frame with levels was needed so that the eastern half of metal decking acting both as permanent the frame could be demolished and rein­ formwork and in composite action with the stated to match the generally retained levels beams. The use of steel was considered to in the other half. Additional floors were also to be of best advantage only if the connection be added to the retained half to sub-divide details could made both repetitive and the large two-storey auditorium space and flexible enough to cope with the dimensional 7. The new three-storey building above the add upper levels. vagaries of the original frame . These criteria refurbished terracotta. A tubular entrance to the office accommoda­ dominated the design development and 8. Concrete deterioration to soffit of tion would link with a vertical circular atrium to detailing of the structural elements. Kahn floor system. integrate the levels and provide vertical The limited storey heights imposed by the access and natural light to the interiors. This original building pushed the choice further in atrium would be treated as an external space the direction of steel. These required a mini­ above first floor level by using a &imple open mum structure and services zone which canopy at roof level with a sealed drained could only be achieved by integrating these glazed canopy at second floor. Above the elements in the same horizontal plane. A existing roof parapet a new three-storey, series of design rules were prepared to glass-clad building would rise to a plant enable the services engineer to determine the level with the building services expressed zonal location and size of tolerable apertures externally. in the steelwork and these were then formed The result is a building which is formal exter­ in the beams using web stiffeners. nally, respecting the heritage of the far;;ades Although a composite deck was chosen for but dramatically light and airy inside. the floor plates, the piecemeal demolition and 17 The ground floor forms a fire barrier between the retail accommodation and the basement car park, and this involved the first upgrading of an existing suspended floor, its western half being retained with the eastern half new­ build . The retained floor exhibited the worst aspects of the inadequately compacted Kahn ribbed units with exposed corroded re­ inforcement in many areas. Each unit was repaired by removing loose concrete, blast cleaning the reinforcing bars, and repairing with SBA modified mortar to achieve dura­ 9 10 bility. Fire resistance was provided by addi­ tional sprayed concrete. To allow excavators access for removing demolition material, the floor was propped in part, with a screed added later to complete the fire rating of four hours. This rather elaborate method of bring­ ing a listed structure up to modern standards calls into question the value of retaining the element. It is difficult to justify the historic value of a 1908 slab repaired with SBA modified mortar, sprayed with concrete, and screeded. The original first floor level (the original auditorium floor) was retained with a new floor to the eastern half. The floor plate is interrupted by the circular atrium void, en­ closed by a stainless steel planar glass canopy suspended by cables from the second floor perimeter beams. Two scenic lifts service the upper floors within the atrium void, which is clad in rainscreen cladding above first floor level. The second floor level is completely new and effectively fills in the mid-level of the audi­ torium in the northern half of the building. At third floor level the western half of the building originally comprised wall beams between the third and fourth floors to span the large auditorium. In this half of the build­ ing the column grid below third floor does not align with that above. The scheme required removal of the walls together with retention of 11

reconstruction required a lateral stability sys­ A pumped drainage system to the sub-base­ tem to be developed which could remain ser­ ment raised the groundwater, which pene­ 9. A detail of the stainless steel canopy within the viceable throughout the works. The original trates the untanked walls up to basement atrium showing the support system for the glazing. stability system - a mixture of framing action level and into a gravity drainage system. In 10. The curved metal and glass atrium. and vierendeel action of the fa<;:ade - would the basement car park, designated as a utility 11 . The cable and boom support system of be severely disrupted during demolition. grade space due to the lack of tanking, the the lower glass roof. Furthermore, the need for flexible steel-to­ existing ground-bearing slab was repaired in 12. At roof level the glass umbrella keeps the concrete connections favoured a simple damaged areas but otherwise remained as worst of the weather from the upper atrium space. original. pinned design, so the rear stair cores were 13. The drama of the office accommodation 1s designed as stability elements with axial load The low strength existing columns at most demonstrated by the old columns meeting the and eccentric lateral loads applied to them lower levels were inadequate to carry the new glass wall. throughout the works. The floor plates act as increased loads from the new building, so to 14 . Maximum contrast was intended between horizontal diaphragms to carry loads to the supplement this a reinforced concrete collar the terracotta fai;:ade and the interior space. cores and the external walls simply assist the was placed around each internal column. The 15. The rear stair cores provide stability and cores in providing overall torsional stability. new collar design was sized to carry the contain high quality concrete finishes with superimposed loading on the floors, with the integral stair support and lighting details. This system provided a number of construc­ original column checked for capacity under tional benefits by permitting the works to be 16. The terracotta reproduction of Donatello's the building's self-weight. The new and old St George gazes down from its arched niche sequentially completed from the bottom concrete is connected by resin-fixed high­ at third floor level above the main entrance. upwards in a traditional manner parallel to the yield dowels. This system enabled fire resis­ core wall construction. tance to be achieved, as well as providing Illustrations 1, 4-6: Reproduced from: At each level of the building the basic design simple flexible connections to the new steel LAKEMAN, A. The YMCA building, Manchester. solution varied.In the sub-basement, trial pits frame. The principle of either collars or cheeks Concrete & Constructional Engineering, Vol. 6. validated the geotechnical desk study and (a thickening on one side of the column only) 1991 . new mass concrete piers were cast to carry to the existing columns was used throughout 2-3: Trevor Slydel new column loads to the sandstone. to effect a repetitive and flexible detail. 7. 9-16: Photos. Peter Mackinven 12 13 / /

18 the third floor but removal of the fourth, The fifth floor is entirely new, being the run­ Conclusion achieved by inserting a pair of steel beams ning track level to the western half of the The result of the highly variable integrated parallel to each wall directly below third floor building. Trimming beams between existing design is a unique blend of heritage and level. A slot was then cut in the wall and a columns support the new three-storey steel­ high-tech. It incorporates several significant central steel column inserted to the fourth framed building above. which has a different construction achievements. which strive to floor level and supporting fourth floor steel­ column grid from the frame below. match those of the original designers, and work. The new fourth floor was then cast on At sixth, seventh and eighth floor levels, which give the building a new lease of life. In top of the existing by using it as a former and cranked steelwork formed from castellated terms of the heritage value of the decision to the wall and floor subsequently removed. universal column sections supports a com­ retain the interior, it is clear that the up­ Consequently a transfer system was installed posite steel deck and a planar solar glass grading to modern standards has completely covered up any original structure. Under without the need for extensive falsework. roof with externally expressed services. these circumstances, the planning conditions imposed are difficult to substantiate. How­ ever, what has been demonstrated is that reinforced concrete structures are extremely adaptable and robust even when relatively poorly constructed and maintained. The resulting accommodation sets an impor­ tant standard for the Manchester office scene and is an example of the true meaning of refurbishment. The irregular nature of the inte­ rior maintains visual interest at all levels with little repetition. St George's statue remains over the resplen­ dent terracotta entrance. in a fa9ade which has seen Manchester's tram system disap­ pear and return, and he is expected to be there well into the next millennium.

Credits Client: Eagle Star Developments Ltd. Architect: Austin Strzala Turner Structural engineer: Ove Arup & Partners Manchester Geoff Bickerton. Steve Burrows. Mark Elsegood. Mark Ruddle. David Hughes Services engineer: W.E.Hannan Associates Quantity surveyor: Banks Wood and Partners Main contractor: Balfour Beatty Building Ltd.

19 US$555M, a three-year construction period, a The challenges December 1985 start date, and a five-month In comparison with most UK motorway pro­ The Kinali-Sakarya mobilization period . This gave an effective jects, the scale of the Kinali-Sakarya project start date of May 1986 and completion by is huge. The contract lengths were typically Motorway, Turkey December 1988. The consortium divided the about 80km - in the UK they only average contract so that the Japanese contractor con­ 15km. As can be imagined, on a project of structed the Second Bosphorus Crossing, the th is size the works were very diverse and Alan Hughes Turkish contractor (STFA) the motorway on challenging, both in scale and technical con­ the European side of the Bosphorus, and the tent. There were many bridges and viaducts. Andrew Lord Italian contractor (IGL) the section on the which prompted the contractor to base his Asian side. design on a standard 40m-long, trough-sec­ tion , precast concrete beam. This article is a sequel to an account by Arups' involvement Andrew Lord in an earlier Arup Journal 1 of In January 1986 Ove Arup & Partners. with some geotechnical problems encountered on joint venture partners ENET (Turkish), and De parts of this job. The present paper takes a Leuw Cather (US), successfully tendered for broader survey of the whole project. as well the supervision contract commencing in May as updating some of the geotechnical 1986. At that time it was thought likely that the aspects. To make the latter intelligible, a successful tenderer might have to raise the certain amount of duplication from the earlier fee money for the supervision contract on the article has been necessary. international money markets. ENET, nomi­ nated as lead consultant, had considered it advisable to include De Leuw Cather in the Introduction joint venture and , because of the then weak­ The Thracian and Anatolian motorway in ness of sterling, for the foreign element of the Turkey forms part of the proposed trans­ bid to be expressed in US dollars. The tender European motorway, commencing in Poland consisted of time basis rates against named and entering Turkey through Bulgaria near posts and defined times in man-months. 169 the old Thracian capital Edirne. The first of the posts were for Turkish nationals and 36 length of this Turkish section, some 36km, for foreigners; of the latter, De Leuw Cather was built between Gebze and lzmit in the took seven leaving Arups with the remaining early 1980s by Turkish contractors. The next 29 , of which six were for short-term visiting section proposed for construction was be­ 2. Deck beam being transported between experts. tween Kinali . the point about 90km west of casting yard and viaduct location. Istanbul on the coast of the Sea of Marmara The part of the construction works supervised 3. Apparatus for launching where the main roads from Greece and by ENET/Arup was in three distinct sections deck beams on structures. Bulgaria meet. and Sakarya, about 160km or Lots: east of Istanbul on the way to the capital city, • Lot 1, on the European side of the Ankara. The two unequal halves of this would Bosphorus. between Kinali and Mahmutbey, adjoin each end of the existing Gebze-lzmit approximately 70km long, and designed by section. Freeman Fox/Botec, consisted partly of dual Four design agencies were commissioned to two-lane and partly dual three-lane motorway design this part of the motorway, which through rolling and mainly agricultural included the Second Bosphorus Crossing . countryside. .They were Freeman Fox, Sir Owen Williams • Lot 3, on the Asian side, was the Camlica­ & Partners, Ove Arup & Partners (each with a Gebze section designed by Arup/ENET: Turkish Joint Venture partner), and Gemas, approximately 45km of dual three-lane a Turkish consulting engineer. The construc­ motorway plus 15km of dual two-lane link tion contract was tendered prior to com­ roads. partly in urban and partly in rural pletion of the detailed design, on the basis of surroundings. a preliminary design from which quantities were estimated. Thus the client invited • Lot 4, also on the Asian side, from west of Of the 18 viaducts involved. the longest was tenders for the construction contract prior to lzmit to east of Adapazari, comprised about the 2km Karasu Viaduct on Lot 1 {front cover awarding the design contract for the Camlica­ 70km of dual two-lane motorway designed by photograph). Arups' supervisory role in­ Gebze section to the group which included Gemas, through semi-urban, very hilly terrain cluded geotechnical appraisal; since the Arups. to low-lying rural agricultural land alongside a original site investigation had only encom­ A consortium of Japanese, Italian. and Tur­ large lake. passed about 300m length at each end of the kish contractors was awarded the con­ Lot 2 was the section including the Second viaduct. Arups recommended further exten­ struction contract, based on a tender of Bosphorus Crossing. sive investigation at alternate pier positions.

1. Route plan of Kinali-Sakarya section of motorway.

10 20 30km

.(""\._" - '\;::::_-.

-- New motorway - design by AruplENET supervision by ENET/Arup1DLC ~ Camlica to Gebze section Sakarya New motorway - superv1s1on by ENET/Arup/DLC ___/' ..i., Kinali to Mahmutbey section \___._ ~ lzmit to Adapazan section ..... - -- - } -- New motorway ; -- Existing motorway / ; ® Section including Second Bosphorus Crossing >

20 4. Approximately Skm section of strata on the lzm1t Bypass. Gemas' original design required the motor­ Cutting Viaduct 3 Viaduct 4 Tunnel 1 Tunnel 2 Viaduct 6 way to pass around the Sarabayir headland. This would have entailed building a rock plat­ form out into the lake to accommodate the diverted existing state road and the main Istanbul-Ankara railway line. with the new motorway occupying the original alignments of road and railway. Arups' original geotech­ rncal appraisal of the problems of embank­ ment construction in a lake in a highly seismic 1 area has been described , the conclusion D Shales and sandstones LJ Fine grained limestone LJ Massive crystalline limestone D Conglomerate being that such a design posed unaccept­ able problems. The recommendation to re­ align the motorway through the Sarabayir As a result, Arups were involved in redesign 1OOm high Agadere Viaduct, back into headland was accepted by the client. of the piling, which eventually were installed another tunnel 700m long, then onto yet Geotechnical problems as large diameter cast in situ concrete piles, another viaduct - all reminiscent of the much The range of geotechnical problems was as bored under bentonite, up to 45m long. Half admired motorway alignments in the Alps. diverse as is ever likely to be met on such a of the Karasu Viaduct was constructed over a In Lot 48, running alongside Lake Sapan9a, construction project. In comparison with the subsequently flooded reservoir. there were several problems to be overcome. UK, the geology of Turkey appears complex; Of the 14 interchanges constructed, six inter­ In the low-lying areas the topsoil thicknesses this is partly due to its the sheer size. which connect with other motorways and vary from were in excess of 1m with thick layers of soft inhibits geological mapping (the best geo­ occupying tight urban locations to spacious clayey silt underneath. A system of transverse logical maps available are at 1: 500 OOO , 1O rural ones. sand drains and sand blanket was used to times poorer than any for the UK). Mainly, The section of Lot 4 (4A) by-passing lzmit stabilize this area over a length of several however, it results from the highly tectonic was particularly challenging, the alignment kilometres. nature of the country, which has caused an crossing a series of deeply incised valleys Surcharging the fills for up to nine months to almost universal faulting and folding of the with intervening high mountains. The topo­ allow the underlying deposits to consolidate strata on a scale seldom experienced in the graphy was such that it required seven via­ was found to be sufficient, although the con­ UK. One consequence of this is that correla­ ducts and two tunnels to carry the motorway tractor on the adjoining contract in exactly the tion of strata encountered in boreholes should only ?km. In one location, it passed from a same conditions found it necessary to pile his always be undertaken with great care - viaduct into a 1200m tunnel, out onto the embankments. there may be one or two faults or folds between boreholes! 5. Tunnel 1 on the lzmit Bypass under construction. The first major problem involved the design of cuttings and embankments in Lot 1 which passed through or were located on land­ slipped Istanbul Green Clay. This was predominantly a mudstone, which after exca­ vation for a cutting would soften very quickly, leading to rapid failure of the cut slopes. The major problem when tackling these areas was the high natural groundwater table, resulting from very high winter rainfalls. In one location near the line of the old Orient Express railway, the motorway had been designed to run through a 26m deep cutting with side-slopes of 1 in 3. During excavation, when the cutting depth had reached 5m the side-slopes became unstable and began to slide. To overcome this problem it was necessary to redesign the vertical alignment of the motor­ way to reduce the maximum cutting depth, and to flatten the side-slopes of the cutting. This resulted in the vertical gradient from the nearby interchange being increased more than was desirable, but this was the optimal solution.

7. Viaducts 3 (background) and 4 (foreground) on the lzmit Bypass under construction.

6. Local work-force.

21 location has triggered a landslip which originally started at a stream about 600m downslope of the motorway but has now rapidly spread uphill to threaten the motorway itself. In such circumstances it may be neces­ sary to provide a bored pile wall solely to support the motorway from the effects of this instability. Slope stability problems also have been experienced elsewhere along the route, par­ ticularly around interchanges and motorway toll booths at Kumburgaz and Mahmutbey, where insufficient land take has created over­ steepened slopes. 8. 15m deep cutting in sidelong ground, Lot 1. Probably the most interesting redesign prob­ lem on the project was connected with the Where alignment or side-slope changes intervals. which had dictated why certain Agadere Viaduct. Part of Arups' geotechnical proved impossible. the 1:3 design side­ areas of the cut had slipped while others appraisal of Lots 1 and 4 involved examina­ slopes were provided with a regular array of didn't. tion of various alignments of the lzmit Bypass counterfort drains sufficient to lower the based on air photo study and site walkovers. groundwater level in the slope and Adjoining this cutting, fill up to 7m high had to A major landslip was identified, involving so ensure stability. However, in one 900m be placed on Istanbul Green Clay which was limestone boulders on one side of the long, 15m deep cutting in sidelong ground, already part of a landslip. In order to avoid Agadere Valley. Responsibility for the design surcharging this already unstable material, counterfort drains were insufficient. Instead it of the viaducts and their foundations was was necessary also to provide a rock fill toe counterfort rock fill trenches up to Sm deep given to the Italian contractor. The Arup weight to support the cut slope. Arups' and 1m wide were dug at approximately Sm report quietly gathered dust for some 2:.-S intervals at right angles to the line of the fill. design report, which recommended that the years, until an earthquake of magnitude 4-5 Capped with a 1.5m thick rock blanket, these rock fill toe should not be constructed in more caused an entire 40m pier of the then uncom­ than 25m lengths at a time, proved particu­ rockfilled trenches transfer the weight of the pleted viaduct to slide down the hillside about fill to the intact clay beneath, and lower the larly prophetic - the hillside was so unstable 300mm. The pier had also tilted, giving a water levels in the landslip debris, so improv­ that it became necessary to install the rock fill horizontal movement of 220mm at the top. ing its stability. in bays of 1Orn maximum length at any one The deck beams had not yet been erected. time, despite dewatering the overlying sandy Unfortunately the advent of the motorway has The precise cause was identified by exten­ layers at the top of the slope. A record of the generated a rash of nearby industrial devel­ sive site investigation: the pier had not been exposed face at the back of the excavation of opment. As a result of a failure to understand founded on solid rock but on some of the the rock fill revealed the full extent of the fault­ and appreciate the slope stability problems, limestone boulders, about 3m across, which ing and folding. sometimes at less than 50m one industrial development in the above the tremor had shifted. Backanalysis of the slip permitted the assessment of residual strength soil parameters for the landslipped debris, which was then used to design the remedial works. The Italian designers of the structure pro­ posed pinning the pier base with micro-piles. This, however, was not successful and even­ tually, after further movements, the base was stabilized with four 3m diameter caissons, one at each corner, extending 25m below the original base level. Extensive slope regrading and drainage works were also incorporated. Much of this redesign was either undertaken by Arups (on behalf of the Turkish Ministry of Public Works and Settlement) or agreed by them in close consultation with the contractor. The foundations to all the piers of the viaduct were also examined, and in some cases redesigned. The landslip also affected the western portal of Tunnel No.2, immediately adjacent to the eastern abutment of the Agadere Viaduct. On a motorway, responsibility for tunnel portal design frequently falls between those con­ cerned with tunnels, with approach viaducts. and with slope stability. The situation was further compounded at the western portal of Tunnel No.1 where an extension to the tunnel portal, with infilling above. was necessary to ensure the stability of the hillside above the tunnel in the event of the maximum predicted

10 11

22 earthquake. The situation was resolved by were safeguarded by the provision of vertical construction contract was let. The client re­ Arups acting as go-between the two design drains, down to the level of Lake Sapanc;a, quired extensive changes early on. resulting consultants, allied to a substantial contribu­ and well uphill of any of these potentially in nine months' extension of time being tion to the design. troublesome areas to avoid seepages on the awarded to the contractor at the end of the exposed face of the cut or any possible build­ first year. Major expropriation problems oc­ For the design of the realigned motorway up of pore water pressures. curred. affecting both the availability of bor­ through the Sarabayir headland at Sapanc;a, Working in Turkey on such a wide range of row areas and the making available of large the site investigation was not entirely conclu­ areas of the site to the contractor. The many sive, largely because of poor recovery, re­ geotechnical problems. with widely differing soil types. afforded the opportunity to work geotechnical problems added to the pattern vealing predominantly granular strata. There of delay, involving both re-design and addi­ was, however, slight evidence of possible alongside Turkish geotechnical engineers and to help them with 'transfer technology'. tional works. Substantial areas of design had clay seams which might just, if continuous, either not been completed or not carried out dip out of the face of the cut, which was to be Contractual aspects at all. For instance, well over 200 small struc­ up to 80m deep. Accordingly Arups advised The contractual aspects were both challeng­ tures, many involving watercourses, had that the cut, to be made over two earthwork ing and interesting. The contract was let on been omitted from the original design of Lot 4 seasons, should first be taken to half its maxi­ an amended form of FIDIC with ENET/ alone. mum depth, with a series of man-sized in­ Arup/DCI as the Engineer under the Contract, spection shafts up to 20m deep to examine and Safettin Sile, ENET's Project Director, The effect of all these changes had to be the strata which would be encountered in the named as the Engineer to act on behalf of the assessed in terms of both time and cost, and remainder of the cut. Examination of the joint venture. of necessity a large amount of Arups' input was attributed to this. Ultimately, as part of exposed faces of the cuts, together with Highway supervision works, because they these inspections shafts, revealed a remark­ are predominantly in the ground, tend to gen­ the site supervision activity. more than 15 man-years of redesign work was carried out able alternating sequence: a yellow brown or erate a large proportion of redesign work. by Arup staff, out of an overall total of 80 reddish brown, very gravelly sand up to Supervising the construction of the works, man-years. 1~ 2m thick alternated with bands of very including necessary redesign, is not the only stiff, light blue, very silty clay, 50-100mm major duty devolving on the supervisory orga­ Financial restraints on the contractor were thick. The clay bands were continuous and nization. It is usual in highway work for many another major issue. The value of the US dollar easily identifiable in the face of the cut - to changes to take place, mainly due to unfore­ fell substantially during the course of the con­ assist in mapping them so as to determine seen ground conditions, expropriation prob­ tract. To allow the work to continue, the client the dip of the strata, each was lettered in turn lems, and changes in client requirements. For introduced a dollar escalation clause into the - very quickly running through the entire instance. on a typical UK motorway of contract to compensate the contractor for his alphabet! c.£25M, well over 1000 Variation Orders will loss of earnings in real terms. The site investigation certainly did not reveal be issued, resulting in many months being Not surprisingly, this contract ran far beyond what was eventually found but the cautious spent by the supervisory staff in revaluing the its original completion date of December approach relying on observational tech­ work, assessing extensions of time, and 1988. The phased opening of sections went niques identified areas of faulting and folding valuing claims. on for three years. and the motorway was not which caused the clay strata to dip out of the It was much more so on this project due to fully open to traffic until autumn 1992. Even at face of the cut. These potential danger areas the incomplete state of the design when the the time of writing, Arups' involvement is not yet finished. Contractual problems invariably lead to disputes and arbitration procedures involving over US$200M are in progress. Depending on the outcome of this. the final value of this contract is likely to be in the order of US$1000M. Reference ( 1) LORD. A. Turkish roads. The Arup Journal, 23(2). pp.20-21. Summer 1988. Credits Client: Turkish Ministry of Public Works and Settlement Designers.· Lot 3; Supervisors: Lots 1, 3, 4: ENET/Arup/De Leuw Cather [Ove Arup & Partners Denms Radcliffe. Alan Hughes. Phil Burch (Pro1ec1 Direclors) Tom Sm11h, John Bevan, Robin Urquhan Jerry Shapley. Phil Salman (resident engineers) Andrew Lord. Terry Gordon. Jan Statham. John Redding. John Gabryhszyn (geo1echnocs) Jack Lawrence. 8 111 Ward (tunnels)) Illustrations: 1, 4: Trevor Slydel 2: The contractor 3: Ove Arup & Partners 5, 6, 13: Harry Sowden 7, 10: Jack Lawrence 8. 9, 11 · Andrew Lord

12 13 9 The Agadere Viaduct (5) between Tunnels 1 and 2 10. Additional reinforcement at the base of Pier 8, for the load to be carried on four 25m deep caissons 11 Western portal of Tunnel 1 12 The motorway, the state road. and the railway 1n the v1c1nity of the Sarabayir headland Tennekelm headland, through which the motorway passes in a cutting, 1s on the far left of the picture 13 The Agadere Viaduct. plus local family

23