Jubilee Line extension


Southwark station and tunnels between Waterloo and London Bridge.

A new underground station has been built at Southwark in South London. It is connected by an escalator link with the main British Rail station at Waterloo as part of the new Jubilee Line extension, connecting Stratford in the East, including the Canary Wharf development, to the centre of London.

Contract 103 involved the construction of this new underground station and link, together with associated structure sand the construction of 2.4km of running tunnel at a depth of 25m below ground level. Bachy Soletanche formed a joint venture with Aoki to act as the main contractors on this section of the new Jubilee Line.

Box construction
The new ticket hall and its basement were built in an open cut box excavation supported by secant piles and the intermediate concourse as a cut and cover structure within 1m x 25m deep diaphragm walls. these walls formed the finish to a 50m long link to Waterloo Station.

Tunnel and shaft construction
The main 4.45 m i.d. tunnels were constructed in London Clay using a roadheader cutting boom mounted in a Dosco shield running 25m beneath 100 year old brick railway viaducts. The tunnels were opened up to 7m i.d. over a 140m length to form the main platform tunnels and a 74m long x 9.2m diameter SGI lined tunnel formed an intermediate concourse. Inclined tunnels, shafts and adits formed the escalator accesses and the emergency and the ventilation accesses to the platform and tunnels.

Compensation grouting and settlement Control
A 1.5m thick grouted slab was formed by compensation grouting to control ground settlement .
Injection was carried out through tube a manchette installed from the surface and horizontally from temporary shafts. A total of 2000m3 grout was injected to control the settlement within 25mm. Sophisticated measuring instruments with associated software were developed to monitor settlement.
In addition, soil nailing was installed above the lower concourse to provide a canopy of reinforced ground over the crown to reduce ground movement and to remove the risk of an inrush from the overlying Thames ground.

Civil, building, mechanical and electrical works
The Joint Venture acted as management contractor for the completion of the above ground civil, building and architectural finishing works and as the Principal Contractor for the total works at the installation and commissioning stages.



Civil engineering

Regardless of site size, and providing it involves a significant proportion of works in the ground, Soletanche Bachy will handle the complete project, and all aspects of the works, including site supervision, excavations, foundations, civil engineering and all construction operations.

Compensation grouting

Tunnel driving inevitably causes surface settlement, following the form of a Gaussian curve, that is a potential source of substantial damage. Compensation grouting is an active technique to offset soil decompression arising from settlement, by injecting precise quantities of grout between the tunnel and the structures exposed to the danger.

Diaphragm wall

A diaphragm wall is a reinforced concrete wall that is made in situ. The trench is prevented from collapsing during excavation, reinforcing and casting by the use of supporting bentonite slurry. The slurry forms a thick deposit (the cake) on the walls of the trench which balances the inward hydraulic forces and prevents water flow into the trench. A slurry made of polymers can also be used.

Tunnel boring

In the tunnelling field, Soletanche Bachy’s subsidiaries Soletanche Bachy Tunnels and CSM Bessac specialise in management of tunnel sites and also, for the latter, the design and construction of tunnel boring machines.



Soletanche Bachy has helped build most of the world's major metro systems, performing soil consolidation grouting and constructing cut-and-cover tunnels with cast-in-situ diaphragm sidewalls, bored tunnels and major underground openings.

Railway works

Soletanche Bachy has developed a number of techniques for use in railway works; cut and cover tunnels, highways, underground stations, viaduct etc.


In the tunnelling field, Soletanche Bachy’s subsidiaries Soletanche Bachy Tunnels and CSM Bessac specialise in management of tunnel sites and also, for the latter, the design and construction of tunnel boring machines.

Voyage au coeur de l'ingénierie de pointe

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