DYNAMIC MODEL TEST FOR RESPONSE OF TUNNEL-STRATUM CROSSING GROUND FISSURE UNDER VIBRATION OF METRO

A tunnel-stratum dynamic response model which crossing ground fissure is designed set in Xi'an subway project. The dynamic model test of the interaction between tunnel and stratum under the subway vibration load is carried out. The dynamic response law of stratum with ground fissure is revealed. The results show the follows. When the ground fissure is not active, the acceleration response of the arch vault is relatively smaller than that of arch bottom. It indicates that the acceleration of arch bottom caused by subway vibration is attenuated significantly when it transfers to the overlying soil through lining. When the hanging wall falls down, the vibration response of the tunnel vault and bottom is obviously stronger than that when the ground fissure is not active. It indicates that, the activity of ground fissure obviously influences the vibration performance of tunnel. Meanwhile, the acceleration amplitude between the hanging and heading wall is obviously different due to the train running position variation and the fall of hanging wall. This effect is unfavorable to the vibration performance of the tunnel, and appropriate measures should be taken to prevent the local damage or destruction of the tunnel lining.