Vibration Response Caused by Silt Layer in Underground Subway under Small Radius Curve Tunnel

The response of the powdered sandy soil to the cyclic load in the operation of the metro in small curves is sensitive, especially the centrifugal force on the track when the train is moving particularly serious, and most areas in Zhengzhou belong to the Yellow River alluvial powdered sand layer, so the metro in long-term operation, due to the dynamic response of the powdered sandy soil layer caused by the settlement of the sandy soil layer, to train operation will bring greater potential problems.In this paper, long-term pore water monitoring was carried out, and the MIDAS finite element calculation platform was used to establish a coupled dynamic model of the metro bed-lining-soil for mutual verification, and the vibration response law of the soil around the tunnel was studied for single train operation and two-way meeting, and for different tunnel burial depths. The results show that the pore water pressure is large in the early stage of train operation, and gradually decreases in the later stage and becomes stable. Due to the influence of peak work hours, seasonal climate, and groundwater level, the pore pressure may cause a small increase, but the overall trend is to decline.the simultaneous passage of two-way trains will cause the pore water pressure to increase more than in the case of one-way train operation due to the load superposition effect, the maximum settlement below the tunnel occurs at the left end of the tunnel, the further away from the tunnel the smaller the settlement; at a certain water table, the tunnel burial depth is positively proportional to the pore water pressure magnitude, and inversely proportional to the settlement of the soil around the tunnel.