LOCAL RESPONSE ACCELERATION METHOD FOR SEISMIC ANALYSIS OF DEEP BURIED UNDERGROUND STRUCTURES

The urban underground structures gradually show the characteristics of larger buried depth, of complicated section and of stereoscopic space. The response displacement method (RDM) and response acceleration method (RAM) recommended by Code for Seismic Design of Urban Rail Transit Structures (GB 50909−2014) have some limitations in the seismic analysis of underground structures with large buried depth or complicated sections. Based on the generalized response displacement method (GRDM) and traditional RAM, this paper proposes the local response acceleration method (LRAM) for the seismic analysis of deep buried underground structures, and this method only needs to determine the acceleration and soil shear stress of the local free field. In combination with a tunnel structure with circle cross section, the validity of the proposed method with different heights of the model and different stiffness of the structure is verified by comparing with the results of the dynamic time history analysis method. The analysis results show that the proposed method is a practical analysis method with a simple operation. When the height of the model is 5 times that of the underground structure, a more accurate structural response can be obtained.