常法向刚度条件下岩石节理剪切-渗流特性试验研究  

Experimental study of shear-seepage behaviour of rock joints under constant normal stiffness

作　　者：夏才初[1] 喻强锋 钱鑫 桂洋 庄小清 XIA Cai-chu;YU Qiang-feng;QIAN Xin;GUI Yang;ZHUANG Xiao-qing(Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院地下建筑与工程系

出　　处：《岩土力学》2020年第1期57-66,77,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金（No.41327001,No.51778475）~~

摘　　要：为研究常刚度(CNS)边界条件下节理的剪切-渗流耦合特性,针对3种不同节理粗糙度的复制节理试样进行了3种不同刚度、3种不同渗透水压力条件下的剪切-渗流试验,全面系统地分析了法向刚度、渗透水压和节理粗糙度等因素对节理剪切过程中力学特性和渗流特性的影响。试验结果表明:节理峰值剪切强度随法向刚度的增加而增加,流量、等效水力开度和透过率随法向刚度的增加而减小;节理峰值剪切强度和法向位移均随渗透水压的增大而减小,流量、等效水力开度和透过率随法向刚度的增加而增加;通过节理面的流量随节理粗糙度的增加而减小。剪切过程中流量、等效水力开度和透过率均呈现类似于节理剪胀的三阶段变化规律:快速增长阶段、增速变缓阶段和稳定阶段;稳定阶段流量随法向刚度和渗透水压的变化近似呈线性关系,随着渗透水压的增加,粗糙程度较高的节理流速较慢。In order to study the shear-flow coupling characteristics of joints under constant normal stiffness(CNS)boundary condition,the shear-flow coupling tests under three different stiffness and seepage pressure settings were carried out for duplicate joint specimens with three different joint roughnesses.Meanwhile,the effects of normal stiffness,seepage pressure and joint roughness on the mechanical properties and seepage characteristics in joint shearing process were systematically analyzed.The test results indicate that the peak shear strength of joint increases with the increase of normal stiffness,while the flow rate,equivalent hydraulic aperture and transmissivity decrease with the increase of normal stiffness;and the flow rate of seepage through joint surfaces during shearing process decreases with the increase of joint roughness.A three-stage change rule of flow rate that is similar to the joint dilatancy is shown in the shearing process:rapid growth stage,slow growth stage,and stable stage.The same rule has also been observed in equivalent hydraulic aperture and transmissivity.During the stable stage,the flow rate is approximately linear with the variation of the normal stiffness and seepage pressure,and the joints with higher roughness present lower flow rate as the seepage pressure increases.

关 键 词：节理 剪切-渗流耦合特性 法向刚度 渗透水压 节理粗糙度 

分 类 号：TU452[建筑科学—岩土工程]