结构-基础-土-河流相互作用地震反应分析

为了研究不同基础形式下河水对成层软土地基上建筑物地震反应的影响,构建了结构-基础-土-河水体系动力相互作用的非线性完全有限元计算模型,在考虑土体重力的前提下,对筏片基础、桩筏基础、箱形基础、桩箱基础相互作用体系进行了时域数值分析。计算结果表明,建筑物靠近河水时,筏基和箱基体系顶部位移发生了向河水一侧的偏移,而采用桩基和桩箱基础时其偏移度明显减小。同种基础形式下,建筑物距河水越远,其框架剪力峰值越大,而不同基础形式的同种工况,桩箱基础时柱剪力最大,筏片基础时最小。单纯筏基和箱基时,基础周围土体均大量进入塑性,上部结构仍保持弹性;而采用下部有桩基础的筏基或箱基时,地基土体只有很少量进入塑性,上部框架结构进入了塑性。

Earthquake response analysis of structure-foundation-soil-river interaction system

In order to study the effect of river on nearby structure on layered medium(soft soil) with different foundations.non-linear interaction finite element model is set up,which is composed of structure,foundation,soil and river.On the basis of considering gravity,this interaction model is analyzed with time domain numerical method.The results show that when the structure on the raft foundation closes to the river,the unrecovered excursion at the top of superstructure takes place,but the excursions of the structures on piled foundation or piled-box foundation are less.For the same foundation form, the farther the structure apart from the river,the bigger the peak shearing force of frame columns will be.Under the same working condition,the peak shearing force of frame columns on the piled-box foundation is the biggest,and that on the raft foundation is the least.The soil around box and raft foundations turns plastic,and the superstructures keep elastic.But the soil around pile-raft and piled-box foundations turns plastic a little,and superstructures turn plastic a lot.