某水电站5号施工支洞洞脸边坡塌滑机制模拟分析
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摘要
某水电站5号施工支洞洞脸边坡,在支洞开挖过程中发生了塌滑现象。用Flac3d模拟施工平台开挖、支洞开挖、降雨等情况下洞脸边坡的变形过程,并结合工程地质条件分析洞脸边坡的塌滑机制。结果表明:洞脸边坡塌滑是开挖和降雨综合作用的结果。开挖打破了边坡原有的平衡状态,边坡岩土体向临空侧有较大变形,但因支护作用边坡尚能处于稳定状态;降雨通过改变坡体孔隙水压力分布和降低岩土体抗剪强度,对洞脸边坡有促滑作用。降雨初期洞脸边坡变形激增,随着后续降雨变形量持续增加直至达到临界状态进而发生失稳塌滑。
The slope at portal of No. 5 adit of a hydropower station has collapsed during the excavation. Flac3d is used to simulate the deformation process of the slope under excavation of construction berm,excavation of adit,rainfall,etc.,and the collapse mechanism of the slope is analyzed with consideration of the engineering geological conditions. The results show that the collapse of the slope is the outcome of excavation and rainfall. The excavation breaks the original stable state of the slope,and the slope rock and soil mass has a large deformation to the empty side. However,thanks to the slope support measures,the slope is still in a stable state; the rainfall changes the pore water pressure distribution and reduces the shear strength of the rock mass of the slope,which facilitates the collapse of the slope. At the initial period of rainfall,the deformation of the slope increased sharply,and the subsequent deformation due to the rainfall continued to increase until it reached a critical state and finally the slope collapsed.
The slope at portal of No. 5 adit of a hydropower station has collapsed during the excavation. Flac3d is used to simulate the deformation process of the slope under excavation of construction berm,excavation of adit,rainfall,etc.,and the collapse mechanism of the slope is analyzed with consideration of the engineering geological conditions. The results show that the collapse of the slope is the outcome of excavation and rainfall. The excavation breaks the original stable state of the slope,and the slope rock and soil mass has a large deformation to the empty side. However,thanks to the slope support measures,the slope is still in a stable state; the rainfall changes the pore water pressure distribution and reduces the shear strength of the rock mass of the slope,which facilitates the collapse of the slope. At the initial period of rainfall,the deformation of the slope increased sharply,and the subsequent deformation due to the rainfall continued to increase until it reached a critical state and finally the slope collapsed.
引文
[1]中华人民共和国国家发展和改革委员会.水电水利工程边坡工程地质勘察技术规程:DL/T 5337-2006[S].北京:中国电力出版社,2006.
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[10]刘斌,徐鹏.某水电站进水II边坡局部塌滑分析与处理[J].甘肃水利水电技术,2015,9(51):22-23.
[11]苏锦豪,何善国,卢建集,等.金鸡滩水利枢纽高边坡塌滑及其整治[J].广西水利水电,2008(03):57-60.
[12]鲁博,游小伟,韦振新,等.某水电站工程1号倾倒变形体成因机制分析[J].西北水电,2014(05):10-13.
[13]乔娟,张立仁,沈英.三峡水库蓄水初期某库岸边坡的失稳机理探究[J].西北水电,2013(05):8-12.
[2]蔡智云,张云,崔淑玲,等.水电站边坡稳定性的三维有限元分析[J].西北水电,2011(03):16-20.
[3]柏俊磊.卸荷条件下某水电站岩质边坡动态开挖稳定性分析[J].西北水电,2013(04):9-12.
[4]郑颖悟,蔺全奎,颜英军.基于FLAC~(3D)强度折减法的某水电站明渠边坡稳定性评价[J].西北水电,2015(06):19-22.
[5]周晓平,雷艳,赵珊等.鲁地拉水电站枯木A滑坡非稳定渗流分析研究[J].西北水电,2013(04):27-31.
[6] E. HOEK.岩石边坡工程[M].卢世宗,等译.北京:冶金工业出版社,1983:9-16.
[7]陈祖煜.土质边坡稳定分析[M].北京:中国水利水电出版社,2003:566-614.
[8]张倬元,王士天.工程地质分析原理[M].北京:地质出版社,2009:278-297.
[9]卞全,苗喆,李学强.某水电站导流洞进口边坡的垮塌及其处理[J].西北水电,2013(06):39-43.
[10]刘斌,徐鹏.某水电站进水II边坡局部塌滑分析与处理[J].甘肃水利水电技术,2015,9(51):22-23.
[11]苏锦豪,何善国,卢建集,等.金鸡滩水利枢纽高边坡塌滑及其整治[J].广西水利水电,2008(03):57-60.
[12]鲁博,游小伟,韦振新,等.某水电站工程1号倾倒变形体成因机制分析[J].西北水电,2014(05):10-13.
[13]乔娟,张立仁,沈英.三峡水库蓄水初期某库岸边坡的失稳机理探究[J].西北水电,2013(05):8-12.