一个考虑剪胀性和应变软化的土体非线性弹性模型  

Nonlinear elastic model for soils incorporating both dilatancy and strain softening

作　　者：陈成[1] 周正明[1] 

机构地区：[1]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,湖北武汉430071

出　　处：《岩土工程学报》2013年第S1期39-43,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家(973)重点基础研究发展计划(2010CB732101)

摘　　要：区别于金属等材料,土体具有压硬性和剪胀性两个基本性质,为非胡克材料,其应力应变关系也区分为应变硬化型和软化型两种。针对三轴排水剪切试验情况,提出了一种新的剪切曲线描述模式和一种新的体变曲线描述模式,两种描述模式均包含4个参数,各参数的物理意义明确且容易确定。结合沈珠江提出的三参数非线性弹性模型,初步提出了一种修正模型。利用一组三轴排水剪切试验数据对提出的修正模型进行了验证,结果表明,该修正模型能较准确地反映土体的应变软化特性和剪胀性,同时还可以描述土体小应变条件下表现出的刚度高度非线性和高模量特征。Different from the metal and other materials,the soils have two basic propertios: pressure-sensitivity and dilatancy,and they do not obey the Hook’s law.Their stress-strain relationship is also divided into two types: the strain hardening and strain softening.For drained triaxial shear tests,a new shear curve describing mode and a new volume deformation curve describing mode are proposed respectively.Each mode contains four parameters,and the physical meaning of each parameter is clear and easy to identify.Combined with the three-parameter nonlinear elastic model by Sheng Zhu-jiang,a modified model is proposed initially.The modified model is verified by the data of a set of drained triaxial shear tests.The results show that the modified model can reflect both strain softening and dilatancy of soils reasonably.In addition,it can also describe the features of soils at small strain state,high nonlinearity of stiffness and high modulus accurately.

关 键 词：非线性弹性模型 应变软化 剪胀性 小应变 

分 类 号：TU411[建筑科学—岩土工程]