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为研究节理裂隙岩体中节理位置和尺寸对岩体综合抗剪强度的影响,以水泥砂浆作为模型材料,通过在试件的不同位置预制相同长度的节理裂隙和相同位置预制不同长度的节理裂隙,进行不同法向压力下3种具有不同起伏角的节理面剪切试验。试验结果表明:当节理位置和长度一定时其抗剪强度随法向压力增加而增加;对于同一节理裂隙,当其位于试件中间时抗剪强度和黏聚力最小,位于试件后端时抗剪强度和黏聚力最大,位于试件前端时介于两者之间;内摩擦角随节理位置的变化规律不明显;当节理裂隙位置固定时,节理裂隙越长,抗剪强度和黏聚力越低,且抗剪强度随节理长度的增加呈近乎线性的减小。节理位置和尺寸对综合抗剪强度的影响可能由于节理、岩桥的强度参数及岩桥内部损伤劣化程度共同作用所致,现场节理岩体的抗剪强度取值应考虑节理的位置影响。
In order to study the effect of joint location and size on joint shear strength of rock mass in jointed fractured rock masses, cement mortar is used as model material to prefabricate joint fractures of the same length and same position in different locations of the specimen. , Under different normal pressures under three kinds of joints with different relief angle shear test. The experimental results show that the shear strength increases with the increase of normal pressure when the joint position and length are constant, and the shear strength and cohesion of the same joint fissure are the smallest when the joint is located in the middle of the specimen. Shear strength and cohesion are the largest, located between the two at the front of the specimen. The variation of internal friction angle with joint position is not obvious. When the position of joint fissure is fixed, the longer the joint fissure, the shear strength and viscosity The lower the cohesion, and the shear strength decreases nearly linearly with the length of the joint. The effect of joint location and size on the synthetic shear strength may be due to the joint effect of joints, strength parameters of rock bridge and damage and deterioration of rock bridge. The value of shear strength of jointed rock mass should take into account the location of joints.