Typical Geodynamic Characteristics Of Zhengzhou And Its Application In Seismic Response Analysis Of Subway Stations

When an earthquake occurs,there is a dynamic interaction between the soil and the underground structure,and the vibration characteristics of the soil around the structure will directly affect the seismic response of the structure,and the deformation of the soil around the structure is an important cause of the damage of the underground structure.Due to the obvious differences in the dynamic characteristics of soil in different regions,the dynamic characteristics of soil in a certain area should be explored when analyzing the seismic structure of the underground structure in a certain area.The construction of rail transit in Zhengzhou is in an important period of large-scale and rapid development,so this paper studies the dynamic characteristics of typical soil in Zhengzhou and the seismic response of subway stations,so as to provide reference for the seismic design of underground structure engineering in Zhengzhou.The main work and research results of this paper are as follows:(1)Through the vibration triaxial test,the dynamic characteristics of the original state and remodeling(silty clay,silty clay)under different confining pressure and different moisture content were explored.The changes of dynamic shear stress,dynamic shear modulus and damping ratio with shear strain amplitude of each sample were analyzed.Through the nonlinear fitting analysis,the nonlinear dynamic characteristic curves and fitting parameters of each sample were obtained.(2)By establishing the finite element analysis model of seismic response of Zhengzhou prototype metro station,the seismic dynamic response of station structure under the action of El-centro wave,Taft wave and org＿wv1 wave with equal peak acceleration was explored.The internal force distribution law of the station structure is obtained,and specific measures are proposed to enhance the seismic performance of the station structure.At the same time,the influence of different seismic waves on the relative horizontal displacement and horizontal acceleration of each component of the station structure was analyzed.Finally,by comprehensively analyzing the spectral characteristics of the input seismic wave and the selfresonance characteristics of the structure,the seismic response law of the spectral characteristics of the input seismic wave to the station structure is obtained.The research results can provide a reference for the seismic design of underground structures in Zhengzhou.