Abstract:In order to investigate general stability during shield tunneling in soft soil stratum, a TJ-TBM2015 multi-functional micro-tunneling test platform is developed independently. The shield shell diameter is changed to simulate the ground loss. By using the dynamic control system, the micro-tunneling boring machine can realize the continuous dynamic mechanical excavation. Based on the test platform, three tests of shield tunneling under different tunnelling conditions are carried out, including no overloading, local overloading and tunneling near the pile group foundation. The surface subsidence and stress variety around tunnel are monitored by transducer to investigate the general stability of different tests, which further give the comparison and discussion on the different test results. The results show that the soil within the one diameter of the tunnel center is greatly affected by tunneling; the influence of local overloading on soil stability is limited, but local overloading may increase the surface settlement; pile group foundation plays a certain role in strengthening and isolating the stratum.