考虑中间主应力与剪胀的新邓肯-张模型  

An Improved Duncan-Chang Model Considering Effects of Intermediate Principal Stress and Shear Dilatancy

作　　者：赵春风[1,2] 杨砚宗[1,2] 张常光[1,2] 赵程[1,2] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092

出　　处：《同济大学学报（自然科学版）》2011年第3期309-313,共5页Journal of Tongji University:Natural Science

基　　金：国家自然科学基金项目(40972180);上海市重点学科建设项目资助(B308);浙江省交通运输厅科技计划项目(2010h35)

摘　　要：邓肯-张模型是岩土工程中广泛应用的非线性弹性模型,但由于其建立在Mohr-Coulomb强度准则基础上,不能考虑中间主应力的影响,且邓肯-张模型应用广义胡克定律时,假定体应变与轴应变之间为双曲线,不能反映岩土材料的剪胀性.基于统一强度理论,在沈珠江模型的基础上,采用二次抛物线体变公式,改进其参数形式,建立同时考虑中间主应力和剪胀的新邓肯-张模型.经与粗粒土和粘性土等试验结果比较,验证了新模型的正确性.研究结果表明:该新模型克服了邓肯-张模型的不足,可以合理地反映岩土材料的中间主应力效应和剪胀性.该结果为邓肯-张模型的改进提供了理论依据,对实际工程设计具有一定的参考价值.Duncan-Chang model is a nonlinear elastic model,which has been widely used in geotechnical engineering.For building on Mohr-Coulomb strength criterion and bulk strain assuming to be hyperbola in generalized Hooke＇s law,Duncan-Chang model can not take the effects of intermediate principal stress and shear dilatancy into consideration.In order to reflect the effects of intermediate principal stress and shear dilatancy rationally,a new Duncan-Chang model is derived on the basis of unified strength theory and SHEN Zhujiang model.A novel parabolic bulk strain expression is adopted in the new model,and some forms of old parameter are improved.The modified model is validated with triaxial compression test results of coarse grained soil and clay.The results show that the new model can overcome the deficiency of the old Duncan-Chang model and reflect the effects of intermediate principal stress and shear dilatancy properly.

关 键 词：邓肯-张模型 统一强度理论 中间主应力 剪胀 

分 类 号：TU521[建筑科学—建筑技术科学]