具有规则粗糙度的类岩石节理剪切力学性质试验研究

(1.重庆大学 土木工程学院 重庆 404500; 2.上海申元岩土工程有限公司 上海 200000; 3.重庆交通大学 国家内河航道整治工程技术研究中心,重庆 400074)

节理; 直剪试验; 剪切力学性质; 剪切强度

Study on shear mechanical properties of rock-like joints with regular roughness
XIE Qiang1, NING Yue1, WANG Jingjing1,2, BAN Yuxin1, FU Xiang3

(1.School of Civil Engineering, Chongqing University, Chongqing 404500; China;2.Shanghai Shenyuan Geotechnical Engineering Co., Ltd., Shanghai 200000, China; 3. National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University, Chongqing 400074, China)

joint, direct shear test, hear behavior, shear strength

DOI: 10.15986/j.1006-7930.2019.010.004

备注

使用水泥砂浆浇筑试样模拟含节理岩石,并设置不同角度的锯齿状节理,进行直剪试验研究其剪切力学特性,以及剪切强度与法向变化规律.试验结果显示,节理面的剪切破坏形式主要受锯齿角度控制,起伏角度较大的节理面,主要发生剪断破坏; 起伏角度较小的情况下则多发生磨损破坏.剪切过程中出现剪胀现象,并在低法向应力和较大锯齿角度下较明显.同一法向应力条件下,节理面抗剪强度基本符合Mohr-Coulomb准则,使用该准则对试验数据拟合得到内摩擦角和粘聚力与节理面锯齿角度呈正相关.分别用Patton和Ladanyi模型分析试验结果,前者在节理面锯齿起伏较小的情况下拟合结果较好,后者则相反.

Cement mortar samples with jagged joints of different angles were made to study their shear mechanical properties, shear strength and normal variation. The results show that the shear failure mode of the joint plane is mainly controlled by the sawtooth angle, the joint surface with larger angle mainly cause shear failure to and occur when the angle is gentle, wearing and tearing often occur. Shear dilatation occurs during the process, especially under lower normal stress and with sharp sawtooth angle. Under the same normal stress condition, the shear strength of the joint surface is positively correlated with the sawtooth angle. This basically meets the Mohr-Coulomb criterion. The cohesive force and internal friction angle of the joint surface obtained by fitting the criterion increase the sawtooth angle. Patton and Ladanyi strength models were used to data analysis. Results show that the former has a better fitting effect on the strength of the joint surface with smaller sawtooth angle, while the latter is better for fitting the joint surface with larger sawtooth angle.