高压渗流作用下砂岩剪切力学特性研究  

Experimental Study on Shear Properties of Sandstone under Osmotic Water Pressure

作　　者：胡斌 丁静 李京 崔凯 马利遥 汤琦 HU Bin;DING Jing;LI Jing;CUI Kai;MA Liyao;TANG Qi(School of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,Wuhan 430081,China)

机构地区：[1]武汉科技大学资源与环境工程学院,湖北武汉430081 [2]冶金矿产资源高效利用与造块湖北省重点实验室,湖北武汉430081

出　　处：《金属矿山》2023年第9期29-36,共8页Metal Mine

基　　金：国家自然科学基金(联合基金)重点项目(编号:U1802243,41672317);湖北省技术创新专项(重大项目)(编号:2017ACA184);武科大重大科技项目培育类创新团队(A类)(编号:2018TDX01)。

摘　　要：水—岩相互作用机制是边坡长期稳定性研究中的关键问题。针对目前水—岩作用研究中试验设计和研究对象与工程实际存在差异,导致边坡岩体渗流损伤机制不明晰的问题,利用自主研发的岩石剪切—渗流耦合试验装置,开展了高压渗流条件下的饱水砂岩剪切试验,分析了渗透水压对砂岩抗剪切强度、剪断面破坏程度以及法向应力—变形影响规律。结果表明:渗透水压对砂岩力学性质具有劣化作用,渗透水压力越大,饱水状态下砂岩抗剪强度、峰值法向变形与峰值剪切变形越小;当砂岩剪应力达到屈服点后,剪应力受裂纹贯通影响,会产生不同程度的剪应力降;在屈服破坏阶段,砂岩法向变形与法向应力变化在时间点上存在对应关系,两者变化规律反映了砂岩内部裂纹在该阶段的扩展情况;在剪切过程中,次级裂纹呈对称出现,随着渗透水压力增大次级裂纹逐渐减少甚至消失,剪断面趋于平整。研究成果可为连续强降雨作用下高陡边坡长期稳定性研究奠定基础。The mechanism of water-rock interaction is a key problem in the study of slope long-term stability.Aiming at the problem that the seepage damage mechanism of slope rock mass is unclear due to the difference between the test design and the research object in the current water-rock interaction study and the actual engineering practice,the shear test of water-satu-rated sandstone under high pressure seepage is carried out by using the rock shear-seepage coupling test device independently developed.The effects of osmotic water pressure on shear strength,shear section failure and normal stress-deformation of sand-stone were investigated.The results show that the mechanical properties of sandstone are degraded by osmotic water pressure,and the shear strength,peak normal deformation and peak shear deformation of sandstone are decreased with the increase of os-motic water pressure.When the shear stress of sandstone reaches the yield point,the shear stress will be affected by the crack connection and produce different degrees of shear stress drop.In the yield failure stage,there is a corresponding relationship between the normal deformation and the change of normal stress at the time point,and their change law reflects the propagation of the internal crack in the sandstone at this stage.In the shear process,the secondary cracks appear symmetrically.With the increase of osmotic water pressure,the secondary cracks gradually reduce or even disappear,and the shear section tends to be flat.The study results can lay a foundation for long-term stability study of high slope under continuous heavy rainfall.

关 键 词：水—岩作用 压剪试验 渗透水压 矿山高陡边坡 抗剪强度 

分 类 号：X936[环境科学与工程—安全科学]