Simulation of cracking near a large underground cavern in a discontinuous rock mass using the expanded distinct element method
Simulation of cracking near a large underground cavern in a discontinuous rock mass using the expanded distinct element method
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DOI：
10.1016/j.ijrmms.2008.05.004
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发表时间：
2009
影响因子：
7.2
通讯作者：
Yujing Jiang;Bo Li;Y. Yamashita
中科院分区：
文献类型：
--
作者：
Yujing Jiang;Bo Li;Y. Yamashita
地下洞室施工场地中的岩体一般不连续，存在不连续面，如层面、节理、断层和裂隙。地下洞室的性能主要取决于洞室附近结构面的力学行为。大量的实验和数值研究已经证明了不连续性对不连续岩体的力学、热学和水力学行为的显著影响，表明不连续岩体中岩石结构的变形机制和稳定性不仅取决于现有的不连续面，而且还取决于主要由于应力重分布引起的新裂纹的产生和随后的持续扩展。开挖在这项研究中，扩展的离散元法（EDEM）的模拟裂纹的产生和扩展，由于剪切和拉伸破坏的基质岩块。利用该方法，对不同洞室深度和不同结构面几何分布的模型进行了深埋地下洞室开挖模拟。利用底部摩擦试验装置进行了模型试验，以验证所提出的数值方法。此外，通过EDEM方法评价了锚杆对控制洞室围岩变形和关键块体移动的支护效果。
The rock masses in a construction site of underground cavern are generally not continuous, due to the presence of discontinuities, such as bedding, joints, faults and fractures. The performance of an underground cavern is principally ruled by the mechanical behaviors of the discontinuities in the vicinity of the cavern. A number of experimental and numerical investigations have demonstrated the significant influences of discontinuities on the mechanical, thermal and hydraulic behaviors of discontinuous rock masses, indicating that the deformation mechanism and stability of rock structures in the discontinuous rock masses depend not only on the existing discontinuities but also on the new cracks generated and thereafter keep propagating due mainly to the stress redistribution induced by excavation. In this study, an expanded distinct element method (EDEM) was developed for simulating the crack generation and propagation due to the shear and tension failures in the matrix rock blocks. Using this method, excavation simulations of deep underground caverns have been carried out on the models with differing depths of cavern and differing geometrical distributions of the existing discontinuities. Model experiments by using the base friction test apparatus were conducted to verify the proposed numerical approach. Furthermore, the support effects of rock bolts on controlling the deformations of the rock mass surrounding a cavern and movements of key blocks were evaluated by means of the EDEM approach.