Abstract:

Based on lumped mass model of soil-structure dynamic interaction system proposed by Penzien, a simplified method of soil-underground structure dynamic interaction system is constructed with the consideration of the shear stiffness and damping characteristic of equivalent soil layers. Shifang Bajiao acceleration record, Songpan acceleration record of Wenchuan earthquake, China in 2008 and a Taft earthquake acceleration record with different frequency spectrum characteristics are selected as bedrock ground motions; then the simplified method and 2D finite element method are employed to analyse seismic responses of soil-subway station structure system. The results indicate that the peak value of acceleration response of subway station structure of the simplified method is more than those of 2D finite element method, and the difference degree is related to the bedrock ground motion characteristics. With the peak value of bedrock ground motion increasing, the difference degree of the results obtained by two methodes is increasing; but the general law is consistent. The simplified method is a good analysis method to analyse the effect of soil-underground structure dynamic interaction; and it can serve as a auxiliary method for aseismic design of underground structure.

Key words: soil-underground structure dynamic interaction, earthquake responses, simplified analysis method