STABILITY ANALYSIS OF TUNNEL FACE IN TWO-LAYER SOILS

In this article, the author carried out two centrifuge model tests simulating tunnels located at cover to diameter C/D of 1.5 and 3.3 in order to investigate the passive failure and deformation mechanisms due to tunneling in two-layer soils including sand and compacted clay. The obtained results show that localized failure mechanism in front of tunnel face is similar to a localized shear failure. The soil in front of the tunnel face moves forward due to the advancing tunnel face, while the ground further away from the tunnel is pushed outwards, causes the effect on the ground surface and thus emerge the ground to create a failure zone.