非饱和土剪切试验颗粒流模拟  

Particle flow simulation for unsaturated soil shear experiment

作　　者：刘小文[1] 查崇伦 LIU Xiaowen;ZHA Chonglun(School of Civil Engineering and Architecture,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学建筑工程学院,江西南昌330031

出　　处：《南昌大学学报（工科版）》2020年第3期242-248,共7页Journal of Nanchang University(Engineering & Technology)

基　　金：国家自然科学基金资助项目(51268046);江西省自然科学基金资助项目(20151BAB203037)。

摘　　要：实验研究基质吸力对非饱和土的变形及强度特性影响耗时耗力,为减少实验所带来的问题,采用颗粒流理论,以颗粒黏结强度为桥梁,建立非饱和土的PFC^3D直剪数值模型,模拟不同固结应力及基质吸力作用下非饱和红土的力学特性,得到其剪切应力与剪切位移的关系。基于摩尔-库伦准则,通过拟合计算得出与基质吸力相关的黏聚力c、内摩擦角φ并与实验值对比;通过黏聚力与基质吸力的关系得到φb角,数值模拟与实验值非常接近,结论验证了模拟的合理性。研究成果为非饱和土性质验证提供了新的思路。The effect of matrix suction on the deformation,strength characteristics of unsaturated soil time-consuming and labor-consuming was investigated.In order to reduce the problems caused by the experiment,the PFC^3D shear numerical model of unsaturated soil was established by using particle flow theory and particle bond strength as bridge.The relationship between shear stress and shear displacement was obtained by simulating the mechanical properties of unsaturated red soil under different consolidation stress and matrix suction.On the basis of Mole-Coulon criterion,the internal friction angle c、cohesion related to matrix suction was obtained by fittingφand compared with the experimental value.Theφb angle was obtained by the relationship between cohesion and matrix suction.The numerical simulation was very close to the experimental value.The rationality of the simulation was verified.The research results provided a new idea for the verification of unsaturated soil properties.

关 键 词：非饱和土 基质吸力 直剪实验 数值模拟 PFC^3D 

分 类 号：TU43[建筑科学—岩土工程]