Study on Anti-floating Failure Mode of Subway Open-Cut Structure in Water-Rich Stratum

The anti-floating design of different stratum structures varies greatly. Anti-floating problems of subway stations in water-rich stratum should arouse people’s attention. The anti-floating failure mode of the subway station in a water-rich stratum is obtained by combining the indoor model test with ABAQUS finite element simulation, and specific anti-floating measures are suggested based on the findings. The typical Xiamen urban rail transit station is used as the research object. The results show that the overall anti-floating failure mechanism of the subway station situated in a water-rich stratum is caused by friction on the sidewall of the station. The floating displacement growth rate is accelerating, yet the structure is not suddenly floating. The strain at the floor and column joint is larger than other parts of the floor. The trend of pore water pressure at the soil under the bottom floor is consistent with the water pressure after the station structure floats. The pore water pressure at the soil under the bottom floor needs to be reduced, and the reduction coefficient is about 0.79-0.85. In the anti-floating design, it should be considered to set up retaining structures such as continuous underground walls to change the seepage path and increase the head loss.