Study On Soil-structure Interaction Under Vertical And Horizontal Seismic Loading

In this paper, with the consideration of the effect of arch of soil and the changes of soilstiffness with depth, the dynamic response of the roof of underground structure under verticalseismic action in the vertical is studied. In addition, the effect of the soil-structure relativestiffness on underground rectangular structure is studied by using pseudo-static method. Inview of the complexity of the determination of frequencies of roof slab of undergroundstructure, this problem is looked at as plane strain problem. Free vibration equation of the roofslab of shallowly buried underground structure is derived. Then by using the boundaryconditions, the frequency equation of the roof slab is obtained. Furthermore, the frequenciesand vibration modes of the roof slab is obtained. It is concluded that rotational stiffness of theside walls has weak effect on the lower frequencies, but has greater impact on the higherfrequencies; moreover, the variation of frequencies of roof slab of underground structure withdepth has been studied by considering the variation of soil stiffness with depth and thevariation of attached mass of soil with depth due to the effect of soil arch. And the effect ofthe soil-structure relative stiffness on underground rectangular structure is gotten by usingpseudo-static method. The obtained results may be served as reference for undergroundstructure seismic design.