地下结构地震反应分析拟静力法与动力非线性时程法的比较

Comparison of pseudo static method and nonlinear dynamic method of subway station structure seismic response analysis

以典型的两层三跨地铁地下车站结构为研究对象,采用基于自由场位移场频域等效线性分析结果的反应位移法和反应加速度法分析地下结构的地震弯矩,并与基于ABAQUS软件的地下结构地震反应非线性时程分析的计算结果进行了比较,对比了不同地震动强度、结构刚度及顶板埋深对地下结构地震弯矩的影响。结果表明:输入地震动强度越大,拟静力法与动力非线性时程法计算结果之间的差异越大;地下结构刚度越大,两者之间的差异也越大;中等强度的地震动作用时,相对于动力非线性时程法的计算结果,浅埋结构的拟静力法结果偏大,深埋结构的拟静力法计算结果偏小;反应位移法和反应加速度法的计算结果差异很小。该研究结果对地下结构抗震设计方法的比选具有一定的指导意义。

Bending moments of a typical three-span and two-story subway station structure was analyzed by response displacement method and response acceleration method using the results of a nonlinear one-dimensional site re- sponse analysis model for vertical propagation of horizontal shear waves. The calculated results were compared to the results of nonlinear dynamic analysis by using software ABAQUS for different ground motion intensity, lateral stiffness and roof cover depth of a subway station structure, the differences are summarized as the following： the computational inaccuracy increasing of pseudo static method with the increasing of ground motion intensity or struc- tural lateral stiffness; the bending moments of the shallow and deep buried subway structure calculated by pseudo static method are larger or less than those calculated by nonlinear dynamic method under moderate-level earth- quake, respectively ; the difference for the calculated results of the response displacement method and the response acceleration method is quite small. The results are used to provide useful reference for the choice of underground structure seismic design methods.