Parsons - 2010 Construction Management for AWV.pdf - SCATnow

Bored Tunnel Alternative Design-Build ProjectDesign-Build Construction Management ServicesSR 99Channel Tunnel Rail LinkLondon, UKPROJECT DETAILSClient Representative:London and Continental RailwaysContract Dates:10/98 - 11/07Total Dollar Amount:$9.2 billionServices Provided:Procurement Manager, Designer,Construction Manager, Engineering SupportDuring ConstructionPROJECT BACKGROUNDThe Channel Tunnel Rail Link (CTRL) is a 68-mile-long high speed rail line linking the existing Channel Tunnel to St. PancrasTerminus Station in London. Some of the major components of the project included:• An 11-mile-long, twin-bore tunnel including a 26.7-foot excavated diameter TBM-driven tunnel under central London,lined with steel-fiber, reinforced concrete segments• A 1.5-mile-long, twin bore tunnel using including a 26.7-foot excavated diameter TBM-driven tunnel under the RiverThames, lined with steel-fiber, reinforced concrete linings, and 4,250 feet of cut-and-cover approach tunnel• A 2-mile-long, single bore, twin track New Austrian Tunneling Method (NATM) tunnel (46 feet equivalent diameter) throughthe North Downs ChalkThe type of tunnel lining varied for each construction type. Steel-fiber, reinforced precast concrete segments were used inconjunction with EPBMs. Associated mechanical and electrical equipment, including the overhead catenary, was installedwithin the tunnels. Final completion of the tunnel included installation of track, slab, and rail, a 2.6-foot-wide inspectionwalkway, a 4.9-foot emergency egress walkway, and fire/life safety systems. The project has won several national engineeringawards.The CTRL project included a state-of-the-art ventilation system to control smoke during fires in the tunnel. The ventilationsystem required the construction of five ventilation shafts within the London section of the project. In addition, the shaftsalso provided emergency egress and pressure relief to reduce transient pressures.Significant Challenges and/or InnovationsThe $9 billion CTRL project was the largest and most complex civil engineering project ever undertaken in Europe, spanning 10years and involving 45 main contractors to construct. The project pioneered the use of steel-fiber, reinforced concrete segmentaltunnel linings for TBM-driven tunnels. This was also the first and largest use of polypropylene fibers in a segmental tunnel liningto improve performance in the event of a fire.The tunnel section in central London passes under approximately 3,000 domestic and industrial buildings, 67 bridges, 7.4miles of surface railways, 600 utility crossings, and under or over eight operational railway tunnels. One of the project team’spriorities was to comprehensively assess potential ground movements and impacts on structures along the alignment.The TBM tunnel construction necessitated extensive underpinning, ground improvement, and monitoring work to protectmany of these structures.Roles of Major ParticipantsHalcrow had overall design responsibility for all underground structures, provided CM services and engineering supportduring construction, and was an integral part of the procurement team.15