关键词: 硬性结构面, 剪切蠕变, 浸水弱化, 粗糙度

Abstract: The hierarchical loading shear creep experiment was carried out for the hard joint surface of sandstone under water immersion and natural state. The normal stress and shear stress of the joint surface was loaded proportionally through uniaxial compression. The experimental results show that before the accelerated creep occurs on the rock joint,the instantaneous deformation caused by the graded loading tends to decrease gradually with the loading stress. Based on the Norton-Bailey model and the Kachanov damage model,a new improved Norton-Bailey creep-shear model was proposed,which involved the joint roughness efficient,immersion conditions,and the ratio of shear stress to normal stress. According to the shear creep experiment data of the sandstone joint surface,the parameters of the creep shear model of the sandstone joint surface under water immersion and natural state were fitted respectively. The results show that the improved Norton-Bailey creep shear model has a good fitting effect on the sandstone joint surface,and can reflect the influence of the weakening effect of water immersion on the joint surface.