干湿循环后贯通型锯齿状红砂岩节理面剪切本构模型  

Shear constitutive model of penetrating sawtooth-like joint surface of red sandstone after dry-wet cycles

作　　者：王桂林[1,2,3] 王力 王润秋 任甲山 WANG Gui-lin;WANG Li;WANG Run-qiu;REN Jia-shan(School of Civil Engineering,Chongqing University,Chongqing 400045,China;National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas,Chongqing University,Chongqing 400045,China;Chongqing Field Scientific Observation Station for Landslide Hazards in Three Gorges Reservoir Area,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学库区环境地质灾害防治国家地方联合工程研究中心,重庆400045 [3]重庆大学三峡库区库岸滑坡灾害重庆市野外科学观测研究站,重庆400045

出　　处：《岩土力学》2025年第3期706-720,共15页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.52378324)。

摘　　要：库岸岩质边坡因受库水位波动影响,节理面受到干湿循环的作用,干湿循环后的节理面剪切强度成为控制岩质边坡稳定性的关键因素之一。目前针对干湿循环后岩体节理面剪切损伤本构等方面研究不充分。以三峡库区红砂岩为例,通过开展不同干湿循环次数下红砂岩的节理直剪试验,获得干湿循环作用下红砂岩的强度变形特征,建立了考虑干湿循环效应的修正Iwan节理面剪切损伤本构模型。结果表明:节理试样的剪切应力-位移曲线形态表现为初始压密、线弹性变形、峰前软化、峰后破坏和残余变形5个阶段;通过引入Logistic模型,节理面剪切损伤本构模型能够反映实际的节理面损伤过程,较好地描述规则锯齿状节理面压密阶段剪切变形行为;干湿循环次数与修正后节理面Iwan剪切损伤本构模型参数存在对数关系;通过室内试验,验证了考虑干湿循环效应的修正Iwan节理面剪切损伤本构模型的准确性,该模型能有效预测干湿循环后节理面剪切应力-剪切位移的关系。研究成果可为三峡库区岩质边坡剪切滑移破坏机制研究和灾害防治提供一定参考。Due to the influence of fluctuation of reservoir water level,the joint surface of rock slope is affected by dry-wet cycles.The shear strength of joint surface after dry-wet cycles becomes one of the key factors to control the stability of rock slope.At present,the research on the shear damage constitutive of rock joint surface after dry-wet cycles is not sufficient.Taking the red sandstone in the Three Gorges Reservoir area as an example,we obtain the strength and deformation characteristics of red sandstone under dry-wet cycles by carrying out joint direct shear tests of red sandstone under different dry-wet cycle numbers,and give a modified Iwan joint surface shear damage constitutive model considering the effect of dry-wet cycles.The results show that the shear stress-displacement curve of the joint specimen is characterized by five stages:initial compaction,linear elastic deformation,pre-peak softening,post-peak failure and residual deformation.By introducing the Logistic model,the shear damage constitutive model of the joint surface can reflect the actual damage process of the joint surface and better describe the shear deformation behavior of the regular serrated joint surface in the compaction stage.There is a logarithmic relationship between the number of dry-wet cycles and the parameters of the modified Iwan shear damage constitutive model.Through laboratory tests,the accuracy of the modified Iwan joint surface shear damage constitutive model considering the effect of dry-wet cycles is verified.The model can effectively predict the relationship between shear stress and shear displacement of joint surface after dry-wet cycles.The research results can provide some reference for the study of shear slip failure mechanism and disaster prevention of rock slopes in the Three Gorges Reservoir area.

关 键 词：红砂岩 节理面 干湿循环 剪切本构模型 

分 类 号：TU441[建筑科学—岩土工程]