金沙江某水电站引水洞出口边坡稳定性分析
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摘要
金沙江某水电站引水洞出口边坡为千枚岩类软岩边坡,其地质条件复杂、结构面发育。由于边坡特殊的岩体结构及其重要性,其稳定发展趋势便成为工程技术人员关心的主要问题。本文在地质调查的基础上,分析了边坡岩体结构特征,建立边坡地质模型,并采用3D-FLAC模拟边坡-洞室组合开挖后的应力、变形分布特征及破坏区范围。结果表明,洞室开挖主要影响6倍洞径范围内围岩应力分布状态,对边坡整体稳定性影响不大;但边坡开挖会使得坡面产生不同程度的受拉区域,对边坡稳定性影响较大。另外,在此基础上选取典型的边坡进行稳定性分析,分析表明,天然状态下,边坡开挖后局部岩体稳定性较差,存在块体失稳的可能,但整体稳定性较好;暴雨、地震条件下,边坡稳定性较差,边坡顶部岩土体有沿结晶灰岩与千枚岩的地层分界面发生失稳的可能。
The slope of water diversion tunnel of a hydropower station at the Jinsha rever is of the soft rock phylitte,where the geological conditions were complex and structural surface developed.As the slope of the rock mass structure and its special importance,the stability trend of the slope had became the major problems,which engineering and technical personnel concerned.In this paper,based on the analysis of structural features of rock slope,the authors established the geological model of slope,and simulated the stress and deformation and damage of the slop after excavation chamber using 3D-FLAC.The results showed that the main impact of the stress distribution by underground excavation would be on the range of 6 times of the diameter of the chamber in the surrounding rock,and that there would be little effect on the overall stability of the slope.But slope excavation would make different degrees of tension in the slopes,which would be put greater impact on slope stability.
The slope of water diversion tunnel of a hydropower station at the Jinsha rever is of the soft rock phylitte,where the geological conditions were complex and structural surface developed.As the slope of the rock mass structure and its special importance,the stability trend of the slope had became the major problems,which engineering and technical personnel concerned.In this paper,based on the analysis of structural features of rock slope,the authors established the geological model of slope,and simulated the stress and deformation and damage of the slop after excavation chamber using 3D-FLAC.The results showed that the main impact of the stress distribution by underground excavation would be on the range of 6 times of the diameter of the chamber in the surrounding rock,and that there would be little effect on the overall stability of the slope.But slope excavation would make different degrees of tension in the slopes,which would be put greater impact on slope stability.
引文
[1]巨能攀.大跨度高边墙地下洞室群围岩稳定性评价及支护方案的系统工程地质研究[D].成都:成都理工大学博士学位论文,2005.
[2]常中华,陈厚军,等.新疆下板地水库地下电站厂房边坡稳定性分析[J].公路交通科技,2005,22(9):48-51.
[3]涂国祥,黄润秋.某水电站坝肩顺坡向边倾角岩质边坡变形破坏机制研究[J].成都理工大学学报(自然科学版),2005,32(3):278-283.
[4]张倬元,王士天,王兰生.工程地质分析原理(第二版)[M].北京:地质出版社,1994.
[5]黄润秋,肖华波.浅埋双连拱隧道围岩-边坡体系变形机理及稳定性分析[J].工程地质学报,2008,16(5):584-590.
[2]常中华,陈厚军,等.新疆下板地水库地下电站厂房边坡稳定性分析[J].公路交通科技,2005,22(9):48-51.
[3]涂国祥,黄润秋.某水电站坝肩顺坡向边倾角岩质边坡变形破坏机制研究[J].成都理工大学学报(自然科学版),2005,32(3):278-283.
[4]张倬元,王士天,王兰生.工程地质分析原理(第二版)[M].北京:地质出版社,1994.
[5]黄润秋,肖华波.浅埋双连拱隧道围岩-边坡体系变形机理及稳定性分析[J].工程地质学报,2008,16(5):584-590.
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