Soft ground

The Thames Tideway Tunnel is an under-construction 25km tunnel running mostly under the tidal section of the River Thames through central London. It will provide capture, storage and conveyance of almost all combined raw sewage and rainwater that currently overflow into the river. Once constructed, the main tunnel will have an internal diameter of 7.2m and will run from -30m at Acton, West London for over 25km under central London down to -70m at Abbey Mills in the East. It will connect 34 of the most polluting combined sewer overflows (CSOs), via transfer tunnels. The tunnel will transfer the captured sewage to the Stratford to East Ham part for onward delivery to Beckton Sewage Treatment Works.

The East Side Access (ESA) project provides new Long Island Rail Road service to the east side of Manhattan, supplementing existing service to Penn Station on Manhattan's west side and Atlantic Terminal in Brooklyn. ESA will serve approximately 162,000 customers a day, providing a faster and easier commute to the east side of Manhattan in a new 8-track terminal and concourse below Grand Central Terminal. The project encompasses more than 13 km of tunnelling.

The TTP are delivering a new two track rail tunnel of approximately 176m length crossing the Highway 401. The purpose of the tracks is to increase capacity along the Kitchener GO commuter rail corridor as well as to accommodate the new Union-Pearson (UO) Express service. The new rail tunnels are mined under the 401/409 Highway using the Sequential Excavation Method (SEM). Our role on this assignment was to provide tunnel design services addressing the challenging conditions (e.g., very low overburden, intercepting piles and maximum settlement allowance) as well as providing on site design representation.

Euston Station will be transformed as the London terminus for HS2. The project involves building a new station alongside the Network Rail station and creating over 600m of new tunnelled connections to the Euston London Underground (LU) station. The works include two new sets of escalators serving the Victoria line and Northern line Bank branch and three new lifts providing step-free access to all lines. Tunnel diameters range from 3.6m to 11.5m with most tunnels being constructed using sprayed concrete lining. In the tightest locations squareworks tunnels have been designed.

Bank Station is a London Underground station located in the City of London financial district. It is a key interchange served by five existing lines. The Bank Station Capacity Upgrade (BSCU) aims to relieve heavy passenger congestion during peak hours for boarding, alighting and interchange. The capacity upgrade comprises the construction of a new southbound platform tunnel and associated length of running tunnel for the Northern line, connecting passageways to the existing station tunnels, and the provision of step-free access from King William Street. The total length of tunnels is 1,300m with tunnel cross sections that range from 10m2 up to 90m2.

Bank Station is a London Underground station located in the City of London financial district. It is a key interchange served by five existing lines. The Bank Station Capacity Upgrade (BSCU) comprises the construction of new tunnels adjacent to and connecting with the existing tunnels. The capacity upgrade includes the construction of 540 metres of running tunnel intercepting with existing foundation piles at four no. building locations. A bespoke solution was developed for each of the buildings and the building impact was assessed in detail.

Bank Station is a London Underground station located in the City of London financial district. It is a key interchange served by five existing lines. The Bank Station Capacity Upgrade (BSCU) comprises the construction of new tunnels adjacent to and connecting with the existing tunnels. Defects surveys of the LU existing facilities predicted to be impacted by the BSCU works had to be carried out before construction started. All existing facilities expected to be within the 1 mm settlement contour were inspected for defects.