基于粘弹性人工边界的掉层结构地震响应分析

Seismic response analysis of structure supported by foundations with different locations based on viscoelastic artificial boundary

为实现山地建筑结构土-结相互作用体系的动力分析,基于粘弹性人工边界理论,利用Matlab编写了用于Abaqus自动施加粘弹性人工边界与外源波动等效节点力的程序,采用该程序模拟的地基无限域外源波动模型的动力响应符合波动理论,验证了该程序的准确性。将采用粘弹性人工边界的土-结相互作用体系与底柱固接的刚性地基分别应用于山地地形掉层框架结构,对模型结构进行动力时程分析,研究陡坎土体土质条件对掉层结构动力响应的影响,计算结果表明,软弱土体陡坎对地震动放大作用较为显著,位于其上的掉层结构的动力响应相较于土质条件较好场地的掉层结构更显不利,需要在结构设计时采取相应措施。

Based on the theory of viscoelastic artificial boundary,a program for Abaqus to automatically apply the equivalent nodal force of viscoelastic artificial boundary and exogenous wave is written using matlab.The dynamic response of the infinite field exogenous wave model of the foundation simulated by this program conforms to the wave theory,which verifies the accuracy of the procedure.The soil-structure interaction system using viscoelastic artificial boundaries and the rigid foundation fixed by the bottom column are respectively applied to the frame structure of the mountain topography,and the dynamic time history analysis of the model structure is carried out to study the soil conditions of the steep sill soil.The calculation results show that the amplifying effect of the weak soil ridge on the ground motion is more significant,and the dynamic response of the layered structure located on it is more unfavorable than the layered structure of the site with better soil conditions.Corresponding measures need to be taken during structural design.