The Shard: London's New Skyline

by James Whitworth often time consuming and labor intensive. Normally a site surveying team will compute traverse computa- Byrne Bros is both one of the UK’s and the tions from observations taken with total stations and world’s leading formwork construction com- precise optical plummets. These calculations allow panies. They were appointed by main building the position of the rig to be obtained in the site contractor Mace to carry out the concrete sub- grid coordinates. As the vertical concrete core has structure and superstructure works for Europe’s known offsets from the rig it is therefore possible to tallest building – The Shard in London – in a guarantee the core is being constructed vertically in contract worth more than 64 Mio. Euro (78.5 relation to its design coordinates. Mio. US Dollar). In the summer of 2009, Leica Geosystems was approached by Byrne Bros to Tight Tolerances develop a real-time slip-form rig positioning sys- The required tolerance for The Shard project was tem, used to construct the central concrete core that rig plan position should not exceed ± 25 mm of The Shard. (± 0.98 in) deviation against the design coordinates. After some consultation between Leica Geosystems The substructure of The Shard adopted ‘top down’ and Byrne Bros a combined system of total stations, techniques and the main structural core was slip- GNSS, and dual axis inclinometers was agreed upon. formed in parallel solutions, which delivered signifi- Real-time GNSS positions allowed determination of cant program advantages. Slip-form construction is the rig’s position. Both the translation and rotation perhaps one of the safest, efficient, and most eco- of the rig could be determined using GNSS technol- nomical methods of building vertical structures. It ogy, but it was unable to provide information on the enables formwork construction to rise at rates of up rig’s inclination which could have been up to ± 75 mm to 8 m (26 ft) in 24 hours. Traditional methods of con- (± 2.95 in) over the 20 m (66 ft) square rig, depending trolling the position of a slip-form rig as it rises are on the correction factors applied by the rig man-

8 | Reporter 67 supply and communication was hard to obtain. Nego power necessary the both provides that location to astable access easy Often difficult. extremely was stations reference stable and reliable of both provision canyon’,the ‘urban the in technology GNSS using ofactually problem to the addition In GeoOffice. Leica within calculated were parameters oftransformation aset correlated to be results station total and GNSS To the allow greater. were window satellite aclear with ties difficul for potential the and level ground near was rig the while particularly results, GNSS the on check simultaneously,gathered which would also provide a to be observations GNSS and station total both allow to antenna AS10 GNSS Leica the with co-located were prisms 360° reason this For calculation. sible pos no even or positions unreliable in resulting nals, buildings canobscure and satellite infrastructure sig Existing challenging. prove often can London in ogy technol GNSS with working city, other any with As System Monitoring Construction aReliable Up Setting Datalogger. Scientific aCampbell via systems the into integrated were and oftilt range expected The inclination sensors were chosen due to the large rig. ofthe corners four ofall position compensated atilt to compute possible was it software Monitoring GeoMoS Leica the within functionality sensor tual vir the using By inclinometers. axis dual four from acquired data using achieved was This rig. the on tilt the to calculate necessary therefore ager. was It ------soft SQL database. An ODBC (Open DataBase Con DataBase (Open ODBC An database. SQL soft aMicro on built is which GeoMoS, ofLeica tecture archi open the used interface positioning rig The position. vertical to the antenna GNSS of the tilt the by caused shift lateral the applying GeoMoS, A computation out was within simultaneously carried speed. wind the and inclinometers axis dual the from data the with synchronized were they where seconds 10 every GeoMoS to Leica sent were observations ofthese result median the and Spider GNSS Leica within second every computed were positions GNSS Computing Positions Every Second quality of better than ± than ofbetter quality coordinate athree-dimensional yielded This away. 2.4 approximately was which station ence refer SmartNet nearest to the respect with puted com was rig the on antenna ofeach position The day. per meters three nearly rose it as rig the on computer site to the nectivity antennas, which guaranteed reliable Internet con directional oftwo comprised system, bridge WLAN a by provided was connectivity Internet service. SmartNet the from stream data areal-time and ers receiv these for streams data incoming the received Spider GNSS Leica rig. the on running computer site to the connected were receivers GMX902GG four The service. correction NRTK SmartNet Leica from feed data areal-time to use decided was it Finally expensive. prohibitively been have could businesses and owners building other with tiation 25 The mm (±mm of LeicaGeosystemsGlobal Magazine |9 0.98 in). km (1.5km mi) ------>>

Renzo Piano, the architect for The Shard, considers (1,017 ft) into the sky and is the tallest building in the the slender, spire like tower a positive addition to European Union. Since its completion in April 2012 it the London skyline. The sophisticated use of glazing soars more than 70 floors above London. The Shard with expressive façades of angled panes is intended houses offices for Transport for London, a hotel, and to reflect light and the changing patterns of the sky, luxury apartments, all with exclusive views over the so that the form of the building will change according capital. to the weather and seasons. The Shard towers 306 m

‘When it comes to structural monitoring, there is no room for risk. It is integral for us to be able to work with a technology that is adaptable to the project and delivers without fail. That’s why we chose Leica Geosystems and that’s why we were able to deliver one of the largest engineering projects with absolute precision.’

Donald Houston, Byrne Bros

nectivity) link was established between the GeoMoS displacement against the design position of ± 4 mm database and the bespoke interface, which displayed per meter (± 0.05 in per foot) of tilt on any corner of the results graphically, so that it was easy to under- the rig, then an orange display was shown. An exag- stand by the rig manager. This interface enabled the gerated rig display and level ‘bubble’ display allowed rig manager to make adjustments to the rig posi- instant visualization of results. tion using hydraulic pumps. A traffic light system of warnings was displayed within the interface. If the Project Results computed results exceeded ± 25 mm (± 0.98 in) lateral This new and innovative approach to controlling the position of a slip-form rig proved highly successful on The Shard project. The fact that the results obtained could be verified and correlated to those obtained via traditional methods was extremely important in building confidence in the system. This, allied to the fact that the Leica Geosystems Monitoring Support team could support this system remotely even 24/7, meant that, particularly in the early stages of this project, confidence in the system was assured. Other tall buildings being constructed in London using slip- form methodology have already adopted this system and Byrne Bros plan to use this system again on future projects.

About the author: James Whitworth is a surveyor with a graduate degree from the University of Newcastle and has the techni- cal lead for monitoring solutions at Leica Geosystems Ltd UK. [email protected]

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