金沙水电站坝肩挠曲边坡稳定性及其影响因素研究
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摘要
针对四川省金沙水电站坝肩挠曲体边坡地质条件的特殊性,基于地勘资料,研究了其地质构造特点、成因机制及失稳破坏模式,运用Hoek-Brown准则对挠曲体边坡岩体力学参数的合理取值进行了分析,并对其稳定性及影响因素进行了研究.研究结果表明:坝肩岩体层间能干性相差大是挠曲体形成的根本原因;对于挠曲边坡,在地勘及室内实验的基础上,运用Hoek-Brown准则确定岩体力学参数是合理的;结构面连通率及降雨条件下挠曲体充水对其稳定性影响显著,随饱和度和连通率的增加,稳定系数均先平稳下降,后急剧下降.依据研究成果,对坝肩挠曲体边坡提出了加固建议,可为类似工程提供参考与借鉴.
According to the particularity of the geological conditions of the abutment flexural slope of Jinsha Hydropower Station in Sichuan Province,based on the analysis of the geodetic survey data,the geological structure characteristics,genetic mechanism and loss of the abutment slope flexure are studied.In the steady failure mode,the least squares method,stochastic-fuzzy method and Hoek-Brown criterion are used to analyze the reasonable values of the rock mass mechanical parameters of the abutment flexural slope,and then the stability of the abutment flexural slope is analyzed.And its influencing factors are studied.The research results indicate:the large difference in inter-layer energy dryness between abutment and rock mass is the root cause of the formation of flexure;on the basis of geological exploration and indoor experiments of the flexural slope,it is reasonable to use the three parameters to determine the value of the mechanical parameters of the rock mass;there is significant influence of structural surface connectivity and water-filling of flexure on its stability under rainfall conditions.With the increase of saturation and connectivity,the stability coefficient decreases first and then decreases sharply.According to the research results,the reinforcement suggestions for the dam abutment flexure slope are proposed,so as to provide reference for similar projects.
According to the particularity of the geological conditions of the abutment flexural slope of Jinsha Hydropower Station in Sichuan Province,based on the analysis of the geodetic survey data,the geological structure characteristics,genetic mechanism and loss of the abutment slope flexure are studied.In the steady failure mode,the least squares method,stochastic-fuzzy method and Hoek-Brown criterion are used to analyze the reasonable values of the rock mass mechanical parameters of the abutment flexural slope,and then the stability of the abutment flexural slope is analyzed.And its influencing factors are studied.The research results indicate:the large difference in inter-layer energy dryness between abutment and rock mass is the root cause of the formation of flexure;on the basis of geological exploration and indoor experiments of the flexural slope,it is reasonable to use the three parameters to determine the value of the mechanical parameters of the rock mass;there is significant influence of structural surface connectivity and water-filling of flexure on its stability under rainfall conditions.With the increase of saturation and connectivity,the stability coefficient decreases first and then decreases sharply.According to the research results,the reinforcement suggestions for the dam abutment flexure slope are proposed,so as to provide reference for similar projects.
引文
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[3]徐卫亚,周家文,石崇.滑石板顺层岩质高边坡稳定性及加固措施研究[J].岩石力学与工程学报,2008,27(7):1423-1435.
[4]雍睿.室内岩体结构面抗剪强度参数取值方法研究[D].武汉:中国地质大学,2011.
[5]Hoek E,Brown E T.Underground Excavation in Rock[M].London:Institute of Mining and Metallurgy,1980.
[6]朱玺玺,陈从新,夏开宗.基于Hoek-Brown准则的岩体力学参数确定方法[J].长江科学院院报,2015,32(9):111-117.
[7]蒋斌松,蔡美峰,都浩.平面滑动边坡稳定性的解析计算[J].岩石力学与工程学报,2004,23(1):91-94.
[8]Hoek E,Bray J.Rock Slope Engineering[M].London:The Institution of Mining Metallurgy,1997:18-23.
[9]王思敬,马凤山,杜永廉.水库地区的水岩作用及其地质环境影响[J].工程地质学报,1996,4(3):1-9.
[10]刘佑荣,唐辉明.岩体力学[M].武汉:中国地质大学出版社,1999.