基础柔性对土-结构相互作用系统响应影响的一个解析解  

The Effect of Foundation Flexibility on System Response of Dynamic Soil-structure Interaction:An Analytical Solution

作　　者：梁建文[1,2] 金立国[2] LIANG Jianwen;JIN Liguo(State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300354, China;Department of Civil Engineering,Tianjin University , Tianjin 300354 ,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300354 [2]天津大学建筑工程学院土木工程系,天津300354

出　　处：《地震工程学报》2017年第5期799-810,共12页China Earthquake Engineering Journal

基　　金：国家自然科学基金项目(51378348;51578372)

摘　　要：采用波函数展开法,通过SH波入射均匀半空间中二维埋置半圆形刚柔复合基础-单质点模型,推导土-刚柔复合基础-上部结构动力相互作用的解析解,并验证解的正确性。研究表明:基础柔性对于系统响应峰值与系统频率有较大影响。考虑基础柔性后,上部结构相对响应峰值相比全刚性基础结果均有一定减小,且系统频率也会产生向低频偏移的现象。The closed form analytical solution for the effect of foundation flexibility on system response amplitude and system frequency of dynamic soil structure interaction is presented.The wave function expansion method through a two dimensional(2D)out of plane model,in which a single degreeof freedom(SDOF)system is supported by a semi circular rigid flexible composite foundation embedded into a homogeneous half space subjected to plane SH waves,is used.The accuracy of the analytical solution is verified by comparing the results of the rigid foundation SDOF model with the results of the flexible foundation SDOF model.The numerical results are also performed and analyzed.It is shown that foundation flexibility has a strong effect on the system amplitude and system frequency.The analysis shows the dynamic response of the foundation and the relative response of the superstructure are very different to that of the rigid foundation results,especially for the case of small shear velocity of the flexible layer and the small size of the rigid core.The displacement of the rigid core is always larger than that of the rigid foundation.Moreover,the rigid foundation assumption cannot provide the correct deformation of the structure near the base in the actual soil\|structure interaction.The peak of the relative response of the superstructure is also always smaller than that of the rigid foundation,which means the rigid foundation may overestimate the effects of scattering of incident waves and the effective input motion of the foundation.The flexibility of the foundation also significantly affects the system frequency.When considering the flexibility in the analysis,the system frequency defined by the peak of the relative response of the superstructure will shift toward lower frequencies compared with that of the rigid foundation,and the amount of shift is highly dependent on the foundation flexibility.The larger the foundation flexibility,the larger the shift value is.The largest shift value can reach38.9%of the rigid foundation sy

关 键 词：基础柔性 系统响应 系统频率 复合基础 土-结构动力相互作用 波函数展开法 平面SH波 

分 类 号：TU352[建筑科学—结构工程]