Model tests on mechanical characteristics of segment lining structure under multi-layered strata

Aiming at the features of Wuhan Yangtze River Tunnel,that is,a tunnel under high water pressure and across multi-layered strata with widely different hardness,model tests on segment lining structure with different water and earth pressures under the layered strata and single stratum were performed by jointly applying the simulation facilities of shield tunnel-ground complex and rotary water pressure devices.The effect of mechanical characteristics of segment lining structure for shield tunnels under multi-layered strata was analyzed.It was shown that: with the increase of water pressure,the average axial force of segment lining structure increased evidently,and the maximum bending moment increased slightly or did not changed basically;the bending moment of segment lining in the hard rock stratum obviously decreased;the influence on the maximum internal force of segment lining caused by the hard rock in certain region was slight.These results could provide valuable preference to the design of segment lining structure for Wuhan Yangtze River Tunnel.