依托大岗山水电站工程的地下洞室群,运用离散元法模拟了不同地质结构组合切割条件下地下洞室开挖支护过程,研究锚杆支护对不同岩体结构变形、应力状态、损伤区影响的改善作用,探讨了节理岩体中锚杆加固机理。结果表明锚杆加固作用是随着节理相对错动和应力调整逐步发展的;受限于锚杆与结构面这种相互作用机制,锚杆并不能有效改善围岩应力状态;锚杆加固作用主要体现在增强结构面抗剪强度和抗拉强度上,提高了关键块体的安全系数并阻止块体的塌落;通过与监测数据对比表明,离散元锚杆单元模型可反映出工程实践中锚杆对岩体的支护效果。
Abstract
With the underground caverns of Dagangshan hydropower project as background, discrete element program is adopted to simulate the excavation and support processes of underground caverns cut by different geological structures. The research focuses on the effect of bolt on the deformation, stress state and damage zone of different rock structures, and the mechanism of bolt support in jointed rock mass is discussed. The results reveal that the rock bolt gradually takes effect with the relative dislocation of joints and stress adjustment of ground rock. Limited to this interaction mechanism, bolts cannot improve rock stress state effectively. Therefore, the role of bolt strengthening is to enhance the shear strength and tensile strength of joint, improve safety factor of key blocks, and prevent the blocks from collapsing. Comparison with monitoring data manifests that the discrete element model could reflect the effect of rock bolt support in practical engineering.
关键词
锚杆 /
地下洞室群 /
不利地质结构 /
离散元 /
节理 /
大岗山水电站
Key words
bolt /
underground caverns /
adverse geologic structure /
discrete element /
joint /
Dagangshan hydropower station
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参考文献
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基金
国家自然基金项目(51379022,51279202);中央级公益性科研院所基本科研基金(CKSF2014063/YT)
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