节理裂隙滑移对某抽水蓄能电站地下洞室喷砼支护破坏的影响规律

地下岩石工程中的裂隙等岩体结构对喷砼等支护结构的受力、变形及破坏具有重要影响.以某抽水蓄能电站为依托,针对开挖过程中揭露的节理裂隙及其分布特征,采用节理单元和Timoshenko梁单元对大型地下洞室群开挖过程节理的滑移和喷砼的破坏开展了施工全过程分析,研究了开挖过程中顺、反倾向节理裂隙的滑移变形发展规律和喷砼的轴力、剪...

Effects of Joint Slips on Shotcrete Lining Failures in Underground Caverns of Pumped Storage Power Station

Structural planes such as joints in rock masses have an important influence on the deformation,stress,and destruction of the shotcrete linings and other supporting structures in underground caverns.Based on a pumped storage power station,joint elements and Timoshenko beam elements are used to analyze the joint slips and mechanical characteristics of the linings during the excavation process.The development of slipping deformations of dip joints and dip-reverse joints,the evolutions of the axial forces,shear forces and bending moments of the linings and the correlation of the joint positions are studied.Finally,a strength envelope method is used to judge the failure types of the linings in different areas,and the effect of joint slipping on the lining failure is revealed.The results show that the sliding deformations of the dip joints during the excavation is more obvious than those of dip-reverse joints,especially in the high-side wall area.The sliding deformations of dip joints have a significant effect on the deformations of the surrounding rock masses and the linings.The internal forces of the linings at the top arch are affected by the joint slips significantly higher than those at the high-side walls,and the cracking failures of the linings are likely to occur at the top arch and the high-side walls,where the lining intersect with the joints.The failure type of the linings is compression-shear and bending-failure failures.The damage degree of the joint slips on the lining during the excavation process is as follows:high-side wall with dip joints>top arch> high-side wall with dip-reverse joints.