土石混合体大型三轴剪切变形特性及模拟方法  

Characteristics and simulation method of large-scale triaxial shear deformation of soil-rock aggregate mixture

作　　者：罗亚琼 张超 李洁 卢霖 任中俊[2] LUO Yaqiong;ZHANG Chao;LI Jie;LU Lin;REN Zhongjun(School of Architectural Engineering,Kunming University of Science and Technology Oxbridge College,Kunming 650106,Yunnan,China;Hunan University of Science and Technology,Xiangtan 411201,Hunan,China;Chongqing Creation Vocational College,Chongqing 402100,China;Hunan First Normal University,Changsha 410205,Hunan,China)

机构地区：[1]昆明理工大学津桥学院建筑工程学院,云南昆明650106 [2]湖南科技大学土木工程学院,湖南湘潭411201 [3]重庆科创职业学院建筑工程系,重庆402100 [4]湖南第一师范学院数学与统计学院,湖南长沙410205

出　　处：《水利水电技术（中英文）》2023年第5期168-176,共9页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金(51204067);湖南省教育厅科学研究项目(21B0489,19B193);重庆市教委科学技术研究计划项目(KJQN202205403)。

摘　　要：土石混合料是山区高填路基工程常见的填筑材料,其剪切变形特性及模拟方法是路基填筑设计的重要依据,但其研究仍存在诸多问题。【目的】为了更全面弄清多因素影响下土石混合体剪切变形特性,建立一种能够模拟土石混合体剪切变形过程的本构模型。【方法】首先,考虑含石量、含水率、岩性和土性等四种因素,采用正交设计试验方法,开展多因素多水平下土石混合体大型三轴剪切试验研究;然后,引入统计损伤力学理论,建立土石混合体轴向损伤模型和轴向损伤演化模型,进而建立土石混合体统计损伤本构模型,给出模型参数的确定方法;最后,将理论模型曲线与土石混合体剪切试验曲线进行比较。【结果】结果显示:土石混合体轴向剪切变形呈明显的阶段性特征;随着含石量由25%增加至70%,内摩擦角由35.5°近似线性增加至46.8°;内摩擦角不随土性和岩性的改变而显著变化;随着含水率由0增加至5%,内摩擦角由40.2°增加至42.4°,但随着含水率持续增加至试样饱和,内摩擦角逐渐减小至36.8°;此模型能够较好地模拟不同围压条件下土石混合体应力-应变试验曲线。【结论】结果表明:随着围压的增大,应变类型由软化型不断向硬化型转变,体应变由剪胀型不断向剪缩型转变;土石混合体内摩擦角的影响因素主次排序为含石量→含水率→岩性→土性;统计损伤理论能够应用于阐释土石混合体变形力学特性。Soil-rock mixture is a common filling material for high fill subgrade engineering in mountainous areas.Its shear deformation characteristics and simulation method are important basis for subgrade filling design,but there are still many problems in its research.[Objective]In order to fully understand the shear deformation characteristics of soil-rock mixture under the influence of multiple factors and establish a constitutive model that can simulate the shear deformation process of soil-rock mixture,[Methods]firstly,considering the four factors of rock content,water content,lithology and soil properties,the orthogonal design test method is adopted to carry out the large-scale triaxial shear test research of soil-rock mixture under multiple factors and levels.Then,the statistical damage mechanics theory is introduced to establish the axial damage model and the axial damage evolution model of soil-rock mixture,and then the statistical damage constitutive model of soil-rock mixture is established,and the determination method of model parameters is given.Finally,The theoretical model curve is compared with the shear test curve of soilrock mixture.[Results]The result show that the axial shear deformation of soil-rock mixture presents obvious stage characteristics.With the increase of stone content from 25% to 70%,the internal friction angle increases approximately linearly from 35.5°to 46.8°.The internal friction angle does not change significantly with the change of soil properties and lithology.As the water content increases from 0 to 5%,the internal friction angle increases from 40.2°to 42.4°,but as the water content continues to increase to the saturation of the sample,the internal friction angle gradually decreases to 36.8°.The model in this paper can well simulate the stress-strain test curve of soil-rock mixture under different confining pressures.[Conclusion]The result show that with the increase of confining pressure,the strain type changes from softening type to hardening type,and the volume strain chang

关 键 词：土石混合体 大型三轴试验 剪切特性 影响因素 本构模型 

分 类 号：U416.1[交通运输工程—道路与铁道工程]