高层建筑-地下室-桩-土系统的相互作用

Interaction of Tall Building-basement-pile-soil System

针对高层建筑－地下室－桩－土系统的实际情况，将桩土区等效成正交各向异性弹性体，采用乘子型无限元与等参有限元耦合的方法模拟承台－桩－土系统，并根据分枝模态－二步法原理求得上、下部结构之间的惯性耦合项，得到考虑相互作用的修正地震波，作为现有高层建筑结构抗震分析软件的地震输入。根据本文提出的方法，对软土地基上的桩承高层建筑进行实例分析，并对不同土质、不同桩土参数进行了对比分析，为桩承高层建筑的地震反应分析提供一条理论严谨而又方便实用的途径。

Considering the engineering fact of tall building with tall building- basement- base slab- pile- soil system, the following researchs are completed. The pile groups are simulated as orthogonal anisotropic elastic medium. The coupled modelling of multiplier infinite element and isoparametric finite element is introduced to simulate the base slab-pile-soil system. Then according to the principle of dynamic substructure theory, Component Modes-two Steps Method is presented. On the basis of intertia coupling between the superstructure (including basement) and base slab-pile-soil system, the modified earthquake wave, considering interaction effect, can be obtained in the first step of analysis. This wave is used as the earthquake input for the earthquake response analysis of tall building in the second step. The method presented herein opens a strict, convenient and practicable way for the earthquake response analysis of pile- supported tall building with spacious multistoried basements.