【摘要】 现有常规抗震设计方法均假定地基为刚性,忽略场地土非线性性质对基础与上部结构动力特性及地震反应的影响。为了将土的非线性性质更好地应用于现有抗震设计和工程实践中,采用有限元方法,选用Davidenkov地基模型并定义其参数,利用ANSYS重新启动分析方法实现程序对土体材料的非线性模拟。通过算例,对土–结构动力相互作用体系进行ANSYS模拟与分析,充分考虑土的非线性以及土体与结构接触界面的状态非线性,对比了刚性地基条件下与非线性土地基条件下上部结构的动力反应,研究了结构不同高度处动力反应的变化规律,同时考察了不同性质地基土非线性性质对整个SSDI体系位移、速度与加速度非线性反应的影响,进而研究体系的抗震性能。与已有实验研究结果对比表明,本文方法具有很强的实用性,符合土–结构动力相互作用的实际工作机理,为研究土的动力特性并将其应用于工程实践提供了重要的理论依据。更多还原

【Abstract】 In the existing seismic design methods the subgrades are all assumed to be rigid, and the effect of soil nonlinearity on foundation and superstructure is ignored. For applying soil nonlinearity to earthquake-resistant design and engineering practice, finite element method is adopted and the simulation of soil constitutional relationship is realized through choosing the Davidenkov soil model with proper parameters and using the restarting method in ANSYS. In succession, the soil nonlinearity and contact boundary nonlinearity are fully considered through the ANSYS procedure, then the dynamic reaction for the superstructure with rigid foundation is compared with that with nonlinear soil foundation, and the variation of the structural dynamic reaction at different heights is studied. At the same time, the dynamic properties of the soil-structure-dynamic-interaction (SSDI) system about the displacement, velocity and acceleration response of different soil basements are studied. A conclusion is drawn that the finite element method is very practicable based on comparison with the existing test results, and the results agree with the actual working mechanism of SSDI. It will provide theoretical basis for the engineering practice.更多还原