Abstract: Based on the character of typical foundation pit support structure and method in gravel stratum, by establishing reasonable 3-D seismic response analysis numerical simulation, adopting LS-DYNA software, this paper studied the stability, disability mutation process and time-dependence characteristic of foundation pit and continuous concrete wall with steel support under intense earthquake action. The results show that failure happens in very short time; propagation direction of the seismic wave has a great influence on the structure stability, the least favorable angle is 30°-40°.

Key words: earthquake action, underground pit supporting system, destruction, time-dependence characteristic