液化场地高层建筑桩筏基础动力响应试验研究  

Experimental study on the dynamic responses of pile-raft foundation of high-rise building in liquefiable site

作　　者：李雨润 邵鼎松 李赫 王永志[2] LI Yurun;SHAO Dingsong;LI He;WANG Yongzhi(College of Civil Engineering and Transportation,Hebei University of Technology,Tianjin 300401,China;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin,Heilongjiang 150080,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]中国地震局工程力学研究所地震工程与工程振动重点实验室,黑龙江哈尔滨150080

出　　处：《岩石力学与工程学报》2025年第4期1013-1025,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52278340);河北省自然科学基金资助项目(E2023202028);河北省研究生创新资助项目(CXZZSS2024009)。

摘　　要：为探究强震作用下可液化饱和砂土场地中高层建筑桩筏基础的动力响应规律,设计并制作饱和砂土场地–桩筏基础–高层建筑结构体系缩尺模型,利用离心机振动台试验设备,开展不同地震动强度下的动力响应试验。重点分析土层加速度响应、超孔压比变化、高层建筑结构的动力响应特性及桩筏基础的动力响应规律,探讨场地液化与高层建筑桩筏基础体系动力响应之间的关系。结果表明:高层建筑桩筏基础结构增加了地基液化深度,且群桩间土体的孔压消散缓慢;加速度反应谱幅值随土层深度增加而减小;小震下筏板加速度承放大趋势,强震下筏板的加速度响应先放大后减小;随着地震波峰值加速度增大,桩身最大弯矩逐渐下移,中桩桩顶弯矩较大,但角桩、边桩和中桩的弯矩最大值出现在砂土层分界处;地基液化为上部建筑结构带来一定的减震效果。The objective of the current investigation is to delineate the dynamic response mechanism of piled raft foundation supporting high-rise structures in the context of liquefiable sandy soil under the influence of intense seismic activity.Within the scope of this study,a scaled-down model representing the integrated system of saturated sand strata,piled raft foundation,and high-rise edifice has been meticulously designed and fabricated.Utilizing the centrifuge shaking table apparatus,dynamic response assessments under varying degrees of ground motion intensity have been conducted.The study primarily concentrates on the analysis of soil acceleration responses,variations in excess pore water press ratio,dynamic behavior characteristics of high-rise structural systems,and the underlying dynamic response patterns of pile-raft foundations.Furthermore,the investigation delves into the interrelation between soil liquefaction and the dynamic response of the pile-raft foundation system of high-rise buildings.The empirical findings indicate that the piled raft foundation of high-rise buildings exacerbates the depth of soil liquefaction to a certain degree,with the dissipation of pore pressure occurring at a leisurely pace amidst the pile clusters.The amplitude of acceleration response spectra diminishes with the progression of soil depth.During the occurrence of minor seismic events,the acceleration of the raft tends to escalate,whereas,in the case of major seismic events,the acceleration response of the raft exhibits an initial increase followed by a subsequent decrease.As the peak acceleration of seismic waves intensifies,the maximum bending moment experienced by the pile shafts progressively diminishes,with the upper bending moment of the central pile being more pronounced.Moreover,the maximum bending moments of corner piles,side piles,and central piles are observed at the interface between the sandy soil layers.The liquefaction of the foundation soil provides a damping effect for the superstructure to a certain extent.

关 键 词：基础工程 砂土液化 桩筏基础 高层建筑 离心机振动台试验 动力响应 

分 类 号：TU473[建筑科学—结构工程]