Abstract: For quasi-static pushover test of soil-underground structure system, the optimization of model box type and the influence of lateral boundary displacement distribution in the test are studied by the numerical method in this paper. Firstly, a quasi-static pushover test scheme of soil-underground structure system is introduced, and then the free-field finite element model and the soil-structure finite element model of the quasi-static pushover test are established and analyzed. It compares the distributions of the equivalent seismic load, the soil-structure interaction forces, the seismic capacity of the structure and the equivalent plastic strain nephogram of concrete structures under different lateral boundary displacement distributions. The results show that the distribution of the lateral boundary displacement has influences on the distribution of the equivalent seismic load and the soil-structure interaction forces and the structural inner forces. In particular, the lateral boundary displacement distribution has a significant impact on the test results of the multi-story model structure, and may even affect the failure process and weak components of the multi-story model structure. Due to the randomness of seismic load and the diversity of model structure, it is reasonable to use laminar shear box with adjustable lateral displacement distribution in the quasi-static pushover test of soil-underground structure system.

Key words: underground structures, seismic performance, distribution of lateral boundary displacement, quasi-static pushover test, laminar shear box