Mechanical properties of frozen rock mass with two diagonal intersected fractures
Mechanical properties of frozen rock mass with two diagonal intersected fractures
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DOI：
10.1016/j.ijmst.2018.02.005
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发表时间：
2018-07
影响因子：
11.8
通讯作者：
Y. Hao;R. Shan;Jinxun Zhang;Wu Fumei-;Zhiming Guo
中科院分区：
文献类型：
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作者：
Y. Hao;R. Shan;Jinxun Zhang;Wu Fumei-;Zhiming Guo
在前人研究成果的基础上，研究了裂隙形态对含双斜交裂隙岩体力学性质和破坏模式的影响。本研究对含两个交叉裂隙的岩石试件在负温下进行了一系列三轴压缩试验，得出了以下结论。两条交叉裂隙的倾角对岩体的强度和破坏模式有很大影响。含两个裂隙的岩体的强度不能简单地用单裂隙岩体的强度估算方法来估算。当相交角度小于30°时，破坏面从“人工破裂”尖端开始，并延伸到试件的上下端。在倾角较大且相交角度在30°~60°范围内的情况下，破坏面沿这两条裂缝中的一条延伸。岩体的力学参数不仅与迹长有关，还与迹长比有关。利用本文提出的近似公式，可以粗略地计算出强度参数。对于迹长比<lt；0.3(短迹长/长迹长)的岩体，破坏模式取决于迹长较长的裂隙。当迹线长度显著且迹线长度比接近1时，破坏面沿两条裂隙扩展，呈现X型破坏形态。对于中等裂隙、迹长比约为1的岩体，破坏模式与裂隙无关，类似于完整岩石的破坏模式。岩体的强度和弹性模量随裂隙间距的增大而减小，而泊松比与裂隙间距无关。破坏模式可由两条裂缝形成的三角形面积来确定。破坏首先发生在较小的三角形区域，并随着较大三角形的两侧传播。
Based on previous research results, this paper investigated the influence of fracture morphology on mechanical properties and failure modes of rock mass with two diagonal intersected fractures. This study carried out a series of triaxial compression tests on rock-like specimens with two crossed fractures under negative temperature, concluded the following conclusions. The strength and failure modes of rock mass are significantly influenced by the dips of two crossed fractures. The strength of rock mass with two fractures cannot simply be estimated using the method that was developed for the rock mass with a single fracture. When the intersecting angle is less than 30°, the failure plane initiates at the tip of “artificial ruptures” and extends to the upper and lower ends of the specimen. In case of a higher dip and intersecting angle ranging from 30° to 60°, the failure plane propagates along one of these two fractures. The mechanical parameters of rock mass are not only related to the trace length, but also depend on the trace length ratio. One could roughly calculate the strength parameters using the approximation proposed in this paper. For the rock mass with a trace length ratio <0.3 (short trace length/long trace length), the failure mode is dependent on the fracture with a longer trace length. When the trace length becomes significant and the trace length ratio approximates to 1, the failure plane propagates along two fractures, where an X-shaped failure pattern is presented. For the rock mass with moderate fractures and a trace length ratio of approximately 1, the failure mode is independent on fractures, which is similar to the damage pattern of intact rock. The strength and elastic modulus of rock mass decrease with the increase of spacing between fractures, while Poisson's ratio is independent on the spacing. The failure mode can be determined by the area of triangle created by two fractures. Damage occurs at the smaller triangle area first, and propagates with the two sides of the larger triangle.