非饱和土广义有效应力三剪强度准则及验证  

Triple-shear strength criterion based on generalized effective stress for unsaturated soils and verification

作　　者：路祥 胡小荣 LU Xiang;HU Xiaorong(School of Infrastructure Engineering,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学工程建设学院,江西南昌330031

出　　处：《南昌大学学报（工科版）》2022年第4期359-365,共7页Journal of Nanchang University(Engineering & Technology)

基　　金：国家自然科学基金项目(10862004,11362016)。

摘　　要：基于非饱和土广义有效应力原理和三剪强度准则,用广义有效应力对三剪强度准则中的有效应力进行替换,推导得到新的基于广义有效应力的非饱和土三剪强度准则。根据新准则的表达式画出它在π平面上的极限线和p′-q平面上的子午线,并对其极限线和子午线进行特征分析,得到它的外凸型π平面极限线和非外凸型π极限线分界b_(0)值。分析不同的中间主应力影响系数、净平均主应力、饱和度和基质吸力对π平面极限线的影响。新准则不仅能考虑中间主应力影响效应,还能考虑拉压不等效应,它是一系列准则的统一表达形式。当中间主应力影响系数取不同的值时就成为不同的准则,可以向其他准则作非线性逼近。最后为了确定所得到的新的非饱和土强度准则是否正确,采用文献结果验证的方法。验证表明新的基于广义有效应力的三剪强度准则计算结果能够很好地预测文献中的试验结果。Based on principle of generalized effective stress of unsaturated soil with triple-shear strength criterion,using the generalized effective stress to replace the effective stress in triple-shear strength criterion.A new triple-shear strength criterion for unsaturated soil based on generalized effective stress was derived by means of equivalent substitution respectively.According to the expression of the new criterion,draw its limit line on theπplane and its meridian on the p′-q plane.The characteristic of its limit line on theπplane and its meridian were analyzed.At the same time,the boundary value of b_(0)between the convex plane limit line and the non-convex plane limit line was obtained.The effects of different influence coefficient of the principle stress,net mean principle stress,saturation and matric suction on limit line were analyzed.The new criterion can consider not only the influence effect of intermediate principle stress,but also the unequal effect of tension and pressure,which was the unified expression of a series of criteria.When the influence coefficient of the principle stress was different,it become different criterion can be approximated nonlinear to other criterion.Finally,in order to determine whether the new strength criterion of unsaturated soil was correct,the method of literature verification was adopted.The results showed that the new triple-shear strength criterion based on generalized effective stress can well predict the experimental results in the literature.

关 键 词：非饱和土 广义有效应力 三剪强度准则 验证 

分 类 号：TU432[建筑科学—岩土工程]