摘要
裂隙是影响工程岩体稳定的重要因素,而平行双裂隙是一种重要的裂隙分布形式,基于已有的研究成果,开展一系列平行双裂隙类岩石三轴压缩试验,研究裂隙产状对平行双裂隙岩体力学性质和破坏形态的影响。试验结果表明:平行双裂隙岩体强度、弹性模量和泊松比受迹长和迹长比共同影响,受裂隙间距影响较小,随倾角增大,先减小后增大;倾角<30°时,破裂面起始于裂隙端部贯穿岩桥,并沿最大主应力方向发展,倾角在30°~60°之间时,沿其中一条裂隙剪切破坏。迹长和迹长比较小时(贯通率<25%,迹长比<2.5),破坏形态与裂隙无关;迹长较大(贯通率>75%),迹长比较小时(迹长比<1),破坏形态取决于长裂隙;迹长介于两者之间时(贯通率25%~75%),迹长比接近1时,受两条裂隙共同影响。
Cracks significantly influence the stability of rock engineering, and two parallel cracks are the severe distribution forms of cracks. A series of triaxial compression tests were conducted on sandstone specimens with two parallel cracks to investigate the effect of fracture morphology on its mechanical properties and failure modes. The results showed that strength, elastic modulus and Poisson＇s ratio of fractured rock were influenced by both the trace length and the trace length ratio. It was also found that these parameters decreased first, then increased immediately with dip increments, and less varied with spacing between cracks. When the dip angle was less than 30°, the failure plane initiated from crack tips and propagated through the rock bridge along the direction of principal stress. Shear failures localised within one crack, when the angle was between 30° and 60°. For the rock specimen with small trace length and trace length ratio（continuity 25%, trace length ratio 2.5）, failure modes were not influenced by cracks. Failure modes depended on the crack with a longer trace length, when the trace length became significant（continuity degree 75%）, but the trace length ratio remained relatively small（trace length ratio 1）. For the rock with moderate cracks（continuity falls between 25%~75%） and the trace length ratio of approximately 1, failure modes were controlled by two cracks.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第12期3573-3580,3589,共9页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.41572270)~~
关键词
平行双裂隙岩体
裂隙倾角
裂隙间距
迹长
力学性质
two parallel fractured rock
fracture dip
fracture spacing
trace length
mechanical properties
