考虑扰动影响的地基非线性沉降分层总和分析方法  

Layer-wise Summation Method for Nonlinear Settlements of Ground Foundation Considering Disturbance Effect

作　　者：曹文贵[1] 张超[1] 徐赞[1,2] CAO Wengui ZHANG Chao XU Zan(Geotechnical Engineering Institute, Hunan University, Changsha 410082, China College of Civil Engineering, Hunan City University, Yiyang 413000, China)

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082 [2]湖南城市学院土木工程学院,湖南益阳413000

出　　处：《湖南大学学报（自然科学版）》2017年第3期113-119,共7页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51378198);高等学校博士学科点专项科研基金资助项目(20130161110017)~~

摘　　要：为预测工程地基土体沉降,针对受到施工扰动影响的地基土,基于扰动状态概念分别以抗剪强度和相对密实度为扰动参量建立扰动因子函数,从而提出能够考虑扰动影响的地基土修正Duncan-Chang模型.首先,考虑地基土实际应力状态,将地基土沉降变形视为由附加静水压力和附加偏应力引起的两部分变形之和,建立地基土沉降变形分析模型;其次,考虑地基土的应力历史并采用分级加载分析方法,给出了不同埋深地基土初始变形模量的确定方法;然后,基于虎克定律和修正Duncan-Chang模型并采用分级加载分析方法分别建立由附加静水压力和附加偏应力作用下的地基沉降变形计算模型,给出了考虑附加应力影响的地基土变形模量的确定方法;最后,将本文方法应用于工程实例并进行了沉降变形分析.研究结果表明:本文方法在反映地基土扰动程度、应力状态和应力历史等方面具有一定的优越性和可行性,其计算结果符合沉降预测规律.For the ground foundation influenced by the construction disturbance, the disturbance factor functions taking the shear strength and relative density as the disturbed parameters, respectively, were proposed based on the disturbed state concept. By using this function, a modified Duncan-Chang model considering the influence of disturbance was developed to provide a reference for the settlements prediction of ground foundation. Firstly, considering the stress state of ground soil, the analytical model for ground soil was established by idealizing the ground settlement to be the summation of one part caused by additional hydrostatic pressure and the other part by additional deviatory stress. Secondly, considering the stress history of ground soil, the determination method for initial deformation modulus of ground soil at different depths was provided by using the step-loading analysis method. Based on the Hooke＇s law and modified Duncan-Chang model, the models to evaluate the settlement of ground foundation caused by additional hydrostatic pressure and of that by additional deviatory stress were then developed, respectively, by using the step-loading analysis method. The determination method for deformation modulus of ground soil was also given considering the additional stress effect. Finally, the proposed method was applied to a practical project case, and the corresponding settlement analysis was carried out. The results show that the proposed method has superiority and feasibility in the aspects of reflecting disturbance degree, stress state and stress history. The calculated results agree well with the prediction rule of settlement.

关 键 词：地基沉降 分级加载 扰动 应力状态 应力历史 

分 类 号：TU44[建筑科学—岩土工程]