基于设计地震动的地震波斜入射波动输入研究

为建立反映地表非一致性运动的地震动场、建立斜入射地震波与设计地震动之间的联系,将地表设计地震动分量看作斜入射的SV波和P波的叠加,根据固体介质中波的传播理论推导了斜入射SV波和P波时程与设计地震动分量的关系,结合粘弹性人工边界,得到了反映设计地震动的地震波斜入射条件下的解析方式,以此为基础建立了时域计算分析模型.半空间算例验证了该方法具有较好的精度,地表面各点的运动具有非一致特征.为计算大跨度结构非均匀地震动输入情况下的动力响应提供了一种有效的方法.

Study on Oblique Wave Input Based on Seismic Design Component

To establish relation between oblique incidence wave and design seismic component, and structure wave field which can result in non uniform ground motion, in this paper, design seismic component is regarded as result of oblique plane SV wave and oblique plane P wave. According to theory of wave propagating in solid, both incidence angles and amplitudes of the oblique waves have deterministic relation. Based on viscous-spring artificial boundary condition, the time-domain calculating method for dynamic interaction between soil and structure object to obliquely incident seismic waves is developed. Half space example with simple ground motion and Koyna seismic horizontal history proves that the method advised in this paper has good precision and can produce similar seismic response to the design seismic component. With general FEM software, the advised method can easily applied to the dynamic analysis of long span structure with non uniform ground motion.