2400 m埋深地下实验室洞群布置模式优化研究
Optimization of layout pattern of underground laboratory cavern groups with buried depth of 2400 m
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摘要: 深部地下试验室是未来人类开采深部资源的基础,中国锦屏地下实验室是全世界埋深最深的地下实验室,锦屏地下试验室二期#8实验洞的建设或许涉及极深岩石力学研究方向,故拟在#8实验洞内设计开挖多个实验洞群以开展原位力学测试及原理探索。然而,实验洞群的布置模式直接影响地下实验室的长期稳定特性。针对高地应力赋存环境地下实验洞室群开挖,建立了FLAC3D三维数值模型,对比研究了同侧相邻洞室不同间距和异侧洞室不同布置工况下,后续洞室开挖对已建洞室围岩稳定性的影响,并用位移变化值作为地下洞室群布置工况评价指标,判识开挖对已建洞室的影响程度。结果表明:同侧相邻洞室间距8 m,异侧洞室对称布置为最优布置工况。研究成果可直接指导锦屏地下实验室二期#8实验洞内实验洞群的布置设计,为其他高地应力环境下洞室群布置提供参考。Abstract: Deep underground laboratory is the foundation of deep mining resources in the future. Jinping underground laboratory in China is the deepest underground laboratory in the world. The construction of No. 8 experimental cavern may involve the research of deep rock mechanics, so multiple caverns will be designed and excavated to carry out in-situ mechanics tests and principle exploration. However, the stability of underground laboratory is directly influenced by the layout pattern of cavern groups. Therefore, aiming at the excavation of the underground experimental caverns under high geostress, a 3D numerical model is established by FLAC. The influences of excavation of the subsequent caverns on the stability of surrounding rock of excavated caverns are compared, which include different spacings at the same side and different layouts at opposite sides, then the value of displacement is introduced to identify the influences of excavation on the caverns which are built. The result shows that the layout with the spacing of 8 m at the same side and the symmetry at opposite sides is optimal. They may guide the layout of underground cavern groups in Jinping’s No. 8 laboratory. Moreover, it can offer a reference for the layout of other similar underground projects.