地基土特性变化对桩基抗震反应的影响  

Effects of Soil Characteristics on Seismic Responses of Foundation Piles

作　　者：王艳丽[1] 杨小卫[2] 王勇[3] 

机构地区：[1]同济大学地下建筑与工程系,同济大学岩土及地下工程教育部重点实验室,上海200092 [2]中国建筑科学研究院,北京100013 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430070

出　　处：《防灾减灾工程学报》2008年第4期417-421,435,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：中科院岩土力学重点实验室开放研究基金项目(Z110506)资助

摘　　要：地震荷载作用下的桩基动力反应在工程设计中越来越受到重视。基于桩-土-结构整体动力有限元法,结合工程实例,建立有限元分析模型,设置粘弹性人工边界,研究水平地震荷载作用下地基土层特性变化对桩基抗震反应的影响。着重探讨了上软下硬和上硬下软两种土层分布情况下,软硬土层相对厚度及弹模比变化对桩基抗震反应的影响。结果显示:桩基和筏基交接处桩顶截面和软硬土层分界处的桩身截面均可能是内力最大截面,桩顶截面和软硬土分界处桩身截面都应是设计需考虑的控制性截面,地基土层特性变化对于桩基弯矩的影响较剪力的影响显著。The seismic responses of foundation piles have invoked more and more attention in design.With the finite element method of complete dynamic interaction of pile-soil-structure combined with a typical case study in engineering,a finite element analysis model was created with a visco-elastic boundary set at the artificially truncated boundary to study the effects of soil characteristics on seismic responses of foundation piles for the case of horizontal seismic loads.In two cases of top soft and bottom hard and of top hard and bottom soft of the soil profile,seismic responses of foundation piles were studied through the variation of relative thickness and the ratio of elastic moduli of the soil layers.The result shows that crosssections of the pile at the intersection of pile-rafter foundation and at the interface of soft and hard soil layers might be the sections of maximum internal forces so that these sections of the pile should be considered as the control sections in the design of the pile body.Effects of characteristics of the soil profile on the moment of piles are more significant than those on the shear.

关 键 词：桩-土-结构 动力相互作用 地震反应 弹模比 

分 类 号：TU435[建筑科学—岩土工程]