模拟岩石节理试样剪切变形特征和破坏机制研究  

Study of deformability behaviour and failure mechanism by simulating rock joints sample under different loading conditions

作　　者：李海波[1] 刘博[1] 冯海鹏[1] 张磊奇 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,武汉430071 [2]河南省南阳市水利勘测设计院,南阳473063

出　　处：《岩土力学》2008年第7期1741-1746,1752,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金重点项目(No50439030);国家十一五支撑项目(No2006BAB04A06)资助

摘　　要：通过RMT-150C电伺服试验机,利用人工浇注素混凝土节理试样进行了不同剪切变形速率、法向应力和起伏角情况下的剪切试验,研究了节理破坏模式和刚度特征及其与起伏角、剪切变形速率和法向应力之间的关系。研究结果表明,试样破坏模式主要受起伏角控制,小起伏角情况下节理呈现磨损破坏模式,大起伏角情况下节理呈现剪断破坏模式,法向应力和剪切变形速率对节理破坏模式有一定的影响;节理的剪切刚度随剪切变形速率和起伏角的增大而增大,增大幅度随变形速率的增大有减小趋势;节理的剪切刚度随法向应力的增大而增大,基本呈线性关系。提出了考虑剪切速率和起伏角度影响的节理剪切刚度公式,并根据试验结果对剪切刚度公式进行了拟合。Through the RMT-150C testing system, artificial concrete joint samples axe employed to study the shearing stiffness and failure mode for rock joint under different shearing deformation velocities, undulation angles and normal stresses. It is suggested that the failure modes of joint samples are dominated by the undulation angles. Under small undulation angle, the joint samples axe in abrasion failure mode, while under high undulation angles, the joint samples are in snip failure mode. The failure modes of joint sample axe also influenced by the normal stress and shearing deformation velocity. It is also reported that the shearing stiffnesses of joint samples increase with the increasing shearing deformation velocities and undulation angles; and the rising rates tend to decrease with the increment of shearing deformation velocities. As well, the shearing stiffnesses of joint samples linearly increase with the increasing normal stresses. The shear stiffness formula is further presented to consider the effect of shearing deformation velocity and undulation angle. Based on the experimental results, the regression results for the formula are also conducted.

关 键 词：节理 剪切速率 剪切刚度 破坏机制 

分 类 号：TU458[建筑科学—岩土工程]