【摘要】 为了考察桩-土接触效应对结构地震反应的影响,利用有限元软件ABAQUS建立了土-桩-框架二维有限元模型,分别采用损伤塑性模型和动力粘塑性记忆型嵌套面模型模拟混凝土和土体,利用rebar单元模拟混凝土内的钢筋,取得了较好的计算效果。计算分析中采用19条不同频谱的地震波记录,考虑了地震动强度、桩径、摩擦系数等因素,以层间位移角和桩顶最大位移为主要评价指标,揭示相互作用体系的动力响应特性。分析认为,计算结果对桩、土摩擦系数的取值不敏感;不考虑土-桩接触时,近场土体的动力反应与实际情况存在一定的误差,且上部结构和桩基的动力反应会被低估,应该考虑桩-土动力接触效应;地震动强度增加时,随着结构进入塑性状态,低估程度减小;桩径增加时,低估程度没有显著变化,虽然桩基和上部结构的反应都有所减小。更多还原

【Abstract】 In order to evaluate the effect of contact on the earthquake responses of soil-structure interaction(SSI) systems,a 2D finite element model of SSI system was developed by using finite element method(FEM)software named ABAQUS.Damaged plastic model and dynamic visco-plastic memorial nested yield surface model are adopted to model concrete and soil respectively,and rebar element is used to simulate the steel in concrete.19 earthquake records with different frequency contents were used altogether.Influence factors,such as friction coefficient,earthquake intensity and pile dimensions,were evaluated to analyze the dynamic responses of SSI systems by the indexes including story drift angle and peak displacement at pile top.It is concluded that the results are not sensitive to friction coefficient;the dynamic response of the pile and the structure are underestimated and the responses of near field soil have a certain error compared to actual situation,when the soil-pile interaction is not considered;the degree of under-estimation decreases with the increasing of earthquake intensity,but it doesn’t exhibit distinct changes with the increasing of pile dimensions,although the responses of the pile and the structure decrease.更多还原