考虑扰动影响的地基非线性沉降分层总和分析方法

发布时间：2019-05-08 09:43

【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.
[Abstract]:In order to predict the settlement of soil in engineering foundation, the disturbance factor function is established based on the concept of disturbance state based on shear strength and relative compactness as disturbance parameters, aiming at the foundation soil affected by construction disturbance. Therefore, a modified Duncan-Chang model is proposed, which can take into account the influence of disturbance. Firstly, considering the actual stress state of the foundation soil, the settlement deformation of the foundation soil is regarded as the sum of the two parts of deformation caused by the additional hydrostatic pressure and the additional eccentric stress, and the analytical model of the settlement deformation of the foundation soil is established. Secondly, considering the stress history of the foundation soil, the method of determining the initial deformation modulus of the foundation soil with different depth is given by using the hierarchical loading analysis method. Then, based on Hooke's law and modified Duncan-Chang model, the calculation models of foundation settlement and deformation under the action of additional hydrostatic pressure and additional eccentric stress are established by means of hierarchical loading analysis. The method of determining the deformation modulus of foundation soil considering the effect of additional stress is given. Finally, the method is applied to the engineering example and the settlement deformation analysis is carried out. The results show that the proposed method has some advantages and feasibility in reflecting the disturbance degree, stress state and stress history of soil, and the calculation results accord with the settlement prediction law.
【作者单位】：湖南大学岩土工程研究所;湖南城市学院土木工程学院;
【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)~~
【分类号】：TU433

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