Displacement velocity effects on rock fracture shear strengths
Displacement velocity effects on rock fracture shear strengths
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DOI：
10.1016/j.jsg.2016.07.007
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发表时间：
2016-09
影响因子：
3.1
通讯作者：
M. Kleepmek;S. Khamrat;T. Thongprapha;K. Fuenkajorn
中科院分区：
文献类型：
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作者：
M. Kleepmek;S. Khamrat;T. Thongprapha;K. Fuenkajorn
进行三轴剪切试验，以评估位移速度和围压的抗剪强度和拉伸诱导的裂缝和光滑的锯切表面制备在花岗岩，砂岩和泥灰岩标本的扩张的影响。多轴载荷框架用于施加1至18 MPa的围压，位移速度范围为1.15 × 10− 5至1.15 × 10− 2 mm/s。结果表明，光滑锯切面的抗剪强度与位移速度和围压无关。在每一种约束下，粗糙裂缝的峰值和剩余剪切强度以及膨胀率都随着位移速度的增加而增加。剪切面积随围压的增大而增大，位移速率随围压的增大而减小。在高围压下，与速度相关的剪切强度倾向于对坚硬岩石（花岗岩）中的粗糙裂缝起作用，而对较弱岩石（砂岩和泥灰岩）中的较光滑裂缝起作用。一个经验标准，明确纳入剪切速度的影响，提出了描述的峰值和残余剪切强度。该判据与三种试验岩石的试验结果吻合较好。
Triaxial shear tests are performed to assess the effects of displacement velocity and confining pressure on shear strengths and dilations of tension-induced fractures and smooth saw-cut surfaces prepared in granite, sandstone and marl specimens. A polyaxial load frame is used to apply confining pressures between 1 and 18 MPa with displacement velocities ranging from 1.15 × 10−5to 1.15 × 10−2mm/s. The results indicate that the shearing resistances of smooth saw-cut surfaces tend to be independent of the displacement velocity and confining pressure. Under each confinement the peak and residual shear strengths and dilation rates of rough fractures increase with displacement velocities. The sheared-off areas increase when the confining pressure increases, and the displacement rate decreases. The velocity-dependent shear strengths tend to act more under high confining pressures for the rough fractures in strong rock (granite) than for the smoother fractures in weaker rocks (sandstone and marl). An empirical criterion that explicitly incorporates the effects of shear velocity is proposed to describe the peak and residual shear strengths. The criterion fits well to the test results for the three tested rocks.