Crossrail calls on experienced tunnellers
LBA provided Construction Planning services to Mott MacDonald on Crossrail MDC3 as part of the largest construction project in the world
London Bridge Associates (LBA) supported Mott MacDonald with construction planning and programming as part of their multi-disciplinary design services contract, MDC3, on Crossrail Line 1 for Crossrail Ltd. The scope covered the Central Tunnels Section East that included 7km of twin 6m diameter bored running tunnels, three new underground stations (Whitechapel, Liverpool Street and Farringdon), a major underground junction at Stepney Green and ventilation and emergency shafts in four locations. It also included development works on the eastern tunnel portal at Pudding Mill Lane including modifications to sections of the existing main line rail system and a new station and structures for diversion of the Docklands Light Railway (DLR). The project included developing the design options, providing input and assessments for planning submissions and environmental statements.
LBA’s Construction Planning Role
LBA provided Construction Planning services that included development of appropriate, safe and economic construction methodology and construction programmes for use in option selection, design development, cost estimates, and environmental impact assessment.
LBA prepared detailed Construction Planning reports for the Mott MacDonald team for the Central Tunnels Section East. These reports detailed technical work scopes, required enabling works and utility diversions, construction methods, sequences, production rates and programmes, predicted construction traffic and outline worksite layouts and plant schedules for use in noise assessments. These provide the necessary information for the project development of logistic requirements and strategies.
The role developed from previous LBA work supporting Mott MacDonald in their role as Technical Consultant in preparation of submissions and supporting information for the Hybrid Bill for the Central Tunnel sections. This included the three main portals, all of the underground stations, the Thames Crossing, an underground crossover and turnouts and all of the shafts. LBA continued to provide support through the committee process as well as assisting with ongoing design development issues.
LBA has been able to provide experience based construction knowledge for the production of Construction Planning reports, resolution of specific buildability problems and valuable input to option selection and CDM safety workshops. In providing this hands on experience and knowledge the Crossrail team were able to benefit in optimising the designs and providing value as the scheme developed.
The underground structures have complex requirements and constraints and LBA were able to draw on the experience of all of its team in supporting the project offering practical advice on all types of tunnelling including; SCL, handwork, mechanised and TBM construction, piling, diaphragm wall construction, geotechnical engineering, and all forms of major civil engineering construction.
This experience included construction of a large number of underground stations in London and elsewhere including DLR Bank Station, London Bridge station for the Jubilee Line Extension, London Underground Kings Cross Station and work on the Singapore MRT and Hong Kong MTR. The planning has been an evolving process with time chainage and programmes, prepared using Primavera software, being assembled for each location before being incorporated into the overall project programme. This approach enables critical path and risk factors to be studied in detail before integration to test the effect of changes on the overall programme.
Detached from the core members working on Crossrail a smaller independent team undertook an audit of the tunnelling strategy adopted by the project.