The effects of compensation grouting on segmental tunnel linings

The effectiveness of compensation grouting in mitigating surface settlements due to tunnelling subsidence has been widely proven. However, excessive grout pressures may cause deformations of tunnel linings and heaving of the ground surface. At the London Docklands Light Railway Lewisham Extension tunnelling site, the contractor has carried out an extensive monitoring programme to measure ground and building movements due to tunnelling works incorporating compensation grouting. The movements of a building and the tunnel lining due to tunnelling and compensation grouting are presented. Preliminary results from finite element analyses simulating the influence of compensation grouting are also presented.