Dynamic centrifuge tests on seismic response of tunnel in saturated sandy foundation

Tunnels in saturated sandy foundation may subject to severe damage due to earthquake-induced liquefaction.Dynamic centrifuge tests on seismic response of metro tunnel in liquefiable soil are conducted.The seismic response of saturated loose sandy deposit,the uplift and deformation performance of metro tunnel in liquefiable soil are investigated.The effectiveness of cut-off walls in reducing structure uplift is also validated.Test results show that the liquefaction induced inner force in tunnel segments and its uplift are mainly influenced by excess pore pressure and earth pressure increment during earthquake.The cut-off walls prevent liquefied soil from moving toward the bottom of the tunnel,and then the uplift of the tunnel is reduced effectively.