SV 波任意角度入射下地铁车站结构地震响应分析.

The influence of the incident angle of seismic wave on the seismic response of subway station structure has been paid more and more attention by scholars. There is a critical angle when SV wave is oblique incident. When the critical angle is exceeded, the phase difference between horizontal motion and vertical motion of the site will change, at the same time, the site has a large vertical earthquake action under supercritical angle incidence. However, the influence of these characteristics of SV waves on the seismic response of subway stations under supercritical angle incidence has not been reported publicly. In this paper, the finite element software ABAQUS is used to verify the accuracy of the method based on frequency-domain stiffness matrix to solve the scattering problem of SV waves from underground tunnels at any angle, then the seismic responses of two-story three-span subway station structure under Class II, Class III and Class IV site conditions when SV waves are incident in the range of 0 to 80 degrees are studied. The results show that the site has large horizontal and vertical seismic response at the supercritical angle of SV wave in a hard site, which will significantly increase the axial force amplitude of the central column of the station. Compared with the vertical incident case, the axial force amplitude increases upto 3.28 times maximum. At the same time, when the SV wave is incident near the critical angle, the axial force distribution is significantly different from other cases. The maximum moment and shear force of the central column of the station appear when the seismic wave is perpendicularly incident, and the amplitude of the moment and shear force decreases with the increase of the incident angle of SV wave. The dynamic interaction between the station and the surrounding foundation has a certain increasing effect on the horizontal earthquake action of the station structure, and the softer the site, the more obvious the increasing effect. It is suggested that the vertical incidence and the incidence near the critical angle of SV wave should be regarded as unfavorable conditions for seismic design of subway station structure. [ABSTRACT FROM AUTHOR]