采用薄层元素法和有限单元法,研究了形状不规则基础-地基的扭转动力相互作用。对平面形状为“L”形和“C”形的箱形基础和刚性筏板基础的阻抗函数以及基础输入地动进行了比较分析。结果表明,随着凹进部分尺寸的增大,“L”形基础的扭转阻抗降低,它可以用相同扭转惯性矩的正方形基础进行近似等效;而凹进部分对“C”形基础的影响比较小,在凹进部分不太大且频率不太高的情况可以忽略不计。
Dynamic torsional interaction between soil and irregularly shaped foundation is studied by the hybrid of the thin layered element method and the finite element method. The torsional impedance functions and the torsional foundation input motions of L-shaped and C-shaped foundations are compared with those of rectangular foundations. The results show that the torsional impedance functions of L-shaped foundations, which are reduced by the recess, are approximate to those of the square foundations with the equivalent torsional moment. However, the effects of the recess on those of C-shaped foundations can be ignored when the recess is not very large and the frequency is not very high.