Study on the Progressive Failure of Subway Tunnel Foundation with a Single Cave beneath by Simulation Experiment

摘要

A plane strain model was designed for research according to the similarity theory, and under the consideration of the grouting pressure, the progressive failure characteristics of subway tunnel foundation with a single karst cave beneath were analyzed. In the experiment, cylindrical airbag was used to impose a load which simulates the grouting pressure. With the method of step-loading, the changing law of the soil stress and displacement were discussed and the fracture plane was plotted. Furthermore, the ultimate load was obtained.