水对节理岩体剪切特性影响的试验研究  

Test study of effect of water on shear characteristic of rock joint

作　　者：唐佳[1,2] 彭振斌[1] 吴启红[3] 李志平[1] 

机构地区：[1]中南大学地球科学与信息物理学院,长沙410083 [2]中国水电顾问集团中南勘测设计研究院地质工程处,长沙410007 [3]成都大学城乡建设学院,成都610106

出　　处：《中南大学学报（自然科学版）》2014年第4期1232-1236,共5页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50878212);四川省科技计划项目(2013JY0119);成都大学人才引进基金资助项目(2010)

摘　　要：为查明潘口水电站进水口边坡节理的水化剪切性质和变化节理面水质量分数,对不同节理的剪切行为进行室内试验,研究水质量分数对节理剪切性质的影响,探讨节理抗剪强度的水化效应。研究结果表明:岩石内部存在多种晶体结构,当中又由很多晶胞组成。水分子进入到晶胞之间的孔隙,发生水化作用,岩石膨胀,使得岩石表面更加复杂,岩石的某些部位(节理面)变得与原来完全不同。节理面的剪应力和剪切位移的关系曲线符合滑移型破坏曲线的特征,试验所施加正应力的增大导致试验材料的剪切强度也逐渐增大。当正应力变小时,节理面达到剪切强度所需要的剪切位移也变小。当水质量分数加大时,节理的剪切强度明显降低。水质量分数的增大使内摩擦角慢慢减小,节理的黏结力也随之增大,水质量分数超过临界水质量分数时,节理面的黏结力逐渐减小。To find out the hydration shear properties of rock joint in slope of Pankou hydropower station, the water content of joint was changed. To test the shear behavior of joint in laboratory, the effect of water content to the shear characteristic of joint was studied，and the water effect of joint shear strength was analyzed. The results show that： There are many crystal structure and cell composition in the rock. Undering hydration, water molecules enter to the cell between the pore, the rocks occur expansion, making the rock surface become more and more complex, some parts of the rock （joint surface） become completely different with original. The relationship between shear stress and shear displacement can be categorized to the slipping mode. With the increase of normal stress on the joint sample，the shear strength of joint increases correspondingly. And with the decrease of normal stress, the shear displacement to reach the maximum shear strength also decreases. With the increase of water mass fraction, the shear strength of joint decreases obviously. The friction angle will decrease gradually with the increase of water content，while the cohesion of joint will increase. After the water content surpasses its critical value, the cohesion of joint will decrease.

关 键 词：水化作用 岩体节理 剪切特性 强度 

分 类 号：TU457[建筑科学—岩土工程]