考虑实际接触三维粗糙度退化的软岩节理剪胀规律预测模型  

Prediction model for dilation behaviors of soft rock joints considering degradation of actual contact 3D roughness

作　　者：班力壬 杜伟升 候宇航 戚承志 陶志刚[3] BAN Liren;DU Weisheng;HOU Yuhang;QI Chengzhi;TAO Zhigang(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Institute of Deep Earth Sciences,China Institute of Coal Science,Beijing 100013,China;School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]北京建筑大学土木与交通工程学院,北京100044 [2]煤炭科学研究总院有限公司深地科学院,北京100013 [3]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《岩土工程学报》2024年第5期1008-1017,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52208328,52104090);中国煤炭科工集团有限公司科技创新创业资金专项资助项目(2022-MS003)。

摘　　要：为预测岩石节理的剪胀变形行为,分析了恒法向荷载作用下实际接触微凸体三维粗糙度在剪切过程中的退化规律,提出了一个适用于软岩节理的剪胀曲线预测模型。在剪切荷载作用下节理法向位移的变化是节理在三角形微凸体侧面爬坡上升行为与爬越一些微凸体顶点后闭合行为的叠加,爬坡行为与闭合行为引起的位移都正比于节理最大可能剪胀角。最大可能剪胀角退化的实质是实际接触节理微凸体平均等效倾角的退化。通过分析初始剪切与残余应力阶段的节理形貌特征,提出了计算初始最大可能剪胀角与残余应力阶段剪胀角的模型。基于软岩节理不发生突然脆性破坏的假设,进一步通过研究剪切过程中节理微凸体退化规律,量化了最大可能剪胀角的变化规律。定量了节理爬坡行为、闭合行为与最大可能剪胀角之间的关系,进而提出了节理剪胀规律预测模型,通过试验验证了模型的有效性。模型可较准确预测软岩节理的剪胀规律,并可合理描述节理初始阶段剪切压密行为。To predict the shear dilation characters of natural rock joints,a shear dilation prediction model suitable for soft rock joints is proposed to analyze the degradation laws of the actual three-dimensional contact roughness during the shear process under constant normal loads.The change of normal displacement of joints under shear loads is the superposition of joint climbing behaviors at the shear side of triangular asperities and joint closing behaviors after climbing some asperities.The displacement caused by the climbing and closing behaviors is proportional to the maximum possible dilation angle.The essence of the degradation of the maximum possible dilation angle is the degradation of the average equivalent dip angle of the actual contact joint asperities.By analyzing the joint morphology characteristics at the initial shear and residual stress stages,a model for calculating the initial maximum possible dilation angle and the dilation angle at the residual stress stage is proposed.Furthermore,based on the assumption that the soft rock joints do not experience sudden brittle failure,the variation of the maximum possible dilation angle is quantified by studying the degradation laws of the joint asperities during the shear process.The relationship among the joint climbing behaviors,the closing behaviors and the maximum possible dilation angle is quantified,and a joint shear dilation prediction model is proposed.The validity of the new model is verified by the test results.The new model can accurately describe the shear dilation behaviors and the initial shear compaction behaviors of joints.

关 键 词：节理剪胀 形貌退化 微凸体 三维粗糙度 节理形貌 

分 类 号：TU458[建筑科学—岩土工程]