基于修正硬化模型的软土深基坑变形数值分析  

DEFORMATION NUMERICAL ANALYSIS OF DEEP EXCAVATION IN SOFT SOIL BASED ON MODIFIED HARDENING MODEL

作　　者：崔溦[1] 王宁[1] 宋慧芳[1] 

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《岩石力学与工程学报》2013年第S2期4041-4047,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金创新研究群体科学基金(51021004);国家自然科学基金资助项目(50809046)

摘　　要：采用理想弹塑性模型对软土中地下工程开挖造成的变形问题进行分析会导致结果不准确。基于土的修正硬化模型,考虑小应变对其复杂变形特性的影响,以一工程实例为依托,对软土中深基坑开挖引起的连续墙变形和地表沉降进行数值模拟,结果表明:在连续墙变形预测上,理想弹塑性模型(Mohr-Coulomb(MC)模型)预测结果明显偏大,基坑底部以下尤为明显,硬化模型预测规律与监测值一致,但结果偏大;在地表沉降预测上,与修正硬化模型相比,MC模型沉降槽要更宽更深,硬化模型结果偏大。总体来看,修正硬化模型可考虑不同加卸载状态引起的土的刚度变化和低应变性态的影响,在变形数值及其规律预测上,都要优于MC模型和硬化模型。Ideal elastoplastic model used in deformation analysis induced by underground engineering excavation leads to inaccurate prediction. Based on modified hardening soil model,considering the effect of small strain condition on soil behavior,a case study of deep excavation on the deformation of diaphragm wall and settlement of ground surface is numerical analyzed. The results show:according to the movement of diaphragm wall,the prediction result by using ideal elastoplastic mode-Mohr-Coulomb(MC) model is larger than observed deformation,and especially the part below the base of excavation. The result obtained from hardening soil model is consistent with but a little larger than the observed deformation. For the prediction of surface settlement,the trough obtained from MC model is deeper and wider than that obtained from modified hardening soil model,and the settlement from hardening soil model is larger. In general,because modified hardening model can be used to simulate the variation of soil behavior such as modulus and small strain during different loading and unloading states,modified hardening model is superior to MC model and hardening soil model whether in value and regular of deformation prediction.

关 键 词：土力学 软土 修正硬化模型 基坑 变形 小应变 

分 类 号：TU447[建筑科学—岩土工程]