SV波斜入射下高拱坝地震反应分析

基于黏弹性人工边界结合显式有限元法的时域波动分析方法,通过三维平面地震波倾斜入射的输入方法,结合小湾拱坝研究了SV波斜入射对拱坝地震反应的影响。结果表明:SV波斜入射角度对拱坝地震反应的影响规律与P波斜入射作用下的情况有着显著的不同,SV波斜入射角度对拱坝抗震安全性起控制作用部位的低频区的幅值放大系数影响显著,顺河向入射时,幅值放大系数随着入射角度的增加而显著减小;横河向入射时,幅值放大系数随着入射角度的增加而显著增大。

Analysis on seismic responses of high arch dam to SV waves of oblique incidence

This paper studies an input method of oblique plane seismic waves for three-dimensional calculation, which is based on a time-domain wave method coupled to an explicit finite element method with viscous-spring artificial boundary conditions. Application of this method to seismic responses of the Xiaowan arch dam under SV waves of oblique incidence is also examined. The results indicate that the responses of this dam are significantly different from those under P waves. The incidence angles of SV waves can cause more sensitive responses of displacement spectrum in low frequency domain, a range crucial to aseismic safety. Under incidence in stream direction the amplitude magnification coefficient of displacement spectrum is significantly decreased by an increase in its angle, while under incidence in transverse direction the coefficient is significantly increased.