地基–结构动力相互作用体系中数值仿真的研究

 采用数值仿真试验进行结构地震反应的理论和计算分析，将理论分析结果、振动台试验结果和计算机仿真结果三者结合起来，研究和分析地基–结构动力相互作用及其抗震性能。通过数值模拟，解决试验中土压力盒损坏的问题，得到地震动激励下桩–土接触压力峰值的数据，并由此分析桩–土接触压力的大小及其分布规律，提出桩基上的支盘是基础减振的主要构件，并承受动荷载，减轻地震波对上部结构的冲击力，同时消耗上部结构反馈给基础的振动能量。承台和桩基两侧的土压力时程曲线呈反向关系，说明基础在同一时间一侧受压，另一侧受拉。产生这种现象的原因是由于框架结构和承台下的桩–土在振动时的相互作用，并由此导致承台出现转动效应、建筑物产生倾倒的现象。

STUDY ON NUMERICAL SIMULATION FOR DYNAMIC INTERACTION OF SOIL AND STRUCTURE

Combined with results of theory，shaking table test and numerical simulation，dynamical interaction and aseismic capability of soil-structure system are studied and analyzed based on analysis of theory and calculation. The question of ruined earth pressure cell in test is solved，and the contact pressure between soil and pile is found out by the numerical simulation and distributing law of earth pressure. It is explained and sure that branches and disks of the pile are main components of foundation which can reduce shake and bear dynamic load，so they lighten the impact of seismic waves to structure and consume structural seismic energy fed back to foundation. Phenomena of pulling up on one side and pressing down on the other side in the pile foundation are revealed according to reverse relation of time-history curve of earth pressure from the corresponding measuring points on the sides of the pile foundation under seismic action at the same time. The phenomena are produced because of dynamic interaction of structure-pile-soil，which results in that bearing table shows turn effect. This law not only explains essential reason that the buildings are inclined and toppled in the seismic region，but also illuminates and verifies that the aseismic capability of structure plays greatly in the dynamic interaction system.