Study on seismic failure mechanism of shallow buried underground frame structures based on dynamic centrifuge tests

During the Kobe earthquake in 1995, Daikai subway station suffered the severe collapse, which aroused people's more attention to the earthquake damage response of underground structures. In order to investigate the seismic failure mechanism of underground frame structures, a series of 1/50-scaled dynamic centrifuge tests were conducted. To make the underground structures produce a reasonable seismic failure mode in tests, an experi-mental scheme was designed in detail based on the author's previous numerical studies. With the purpose of simulating the vertical inertial effect of the overburden soil in the dynamic centrifuge tests, a certain proportion of steel grits were mixed into the overlying soil. A model structure finally occurred the overall collapse mode, which was similar to that of Daikai subway station. Based dynamic centrifuge tests, the seismic failure mecha-nism of shallow buried underground frame structure was analyzed and summarized in the paper. It could offer a reference for the cause of collapse of Daikai subway station. The series of tests provided valuable experimental data for further studies of the earthquake damage response of underground frame structures, and also enriched the testing technique for destructive model tests.