汉江孤山航电枢纽工程区近坝滑坡稳定性分析及防治工程建议

Stability of near-dam landslides and engineering countermeasures on Gushan marine power station project

汉江孤山航电枢纽近坝河段从下游至上游分别发育陈家咀、罗行滩和青石梁等3处滑坡,对大坝安全构成重大危害,陈家咀滑坡为大型岩质切层滑坡,规模约2.40×10~6m^3,罗行滩滑坡为中型堆积层滑坡,规模约7.0×10~5m^3,青石梁滑坡为中型岩质顺层滑坡,规模约8.1×10~5m^3; 3处滑坡现状整体均基本稳定,水库运行后或建坝前后叠加暴雨久雨滑体饱水等多种工况下处于欠稳定-不稳定状态;罗行滩滑坡主要危及大坝右岸施工道路、围堰工程和水工建筑物的安全,陈家咀滑坡若失稳主要影响大坝泄洪能力、通航安全和电站出力,青石梁滑坡对枢纽工程的影响主要为滑坡涌浪造成的次生灾害,此外滑坡还危及滑体上居民和基础设施安全,以及影响汉江行洪、航运等,地质灾害危害程度大,危险性大。建议,陈家咀滑坡采用抗滑桩+抛石压脚+排水等工程措施,罗行滩滑坡和青石梁滑坡采用以削方减载+排水为主的工程措施,并开展变形监测,以消除滑坡灾害。

From the downstream to the upper reaches of the Gushan Navigation and Power Hub of the Hanjiang River,there are three landslides,Chen Jiazui,Luohongtan and Qingshiliang,which pose a great harm to the safety of the dam.Chenjiazui Landslide is a large rock-cut layer landslide with a scale of 2 400 000 m^3,the Luohongtan Landslide is a middle-sized accumulation layer landslide,the scale is about 700 000 m^3,and the Qingshiliang Landslide is a medium rock bedding landslide.The present situation of the landslide at 810 000 m^3.Near-dam landslide is basically stable at present,but could be in an understable or unstable state when the reservoir is in operation or under the condition of superimposed heavy rain,excessive rain and saturated slide body,etc.The Luohongtan Landslide mainly endangers the construction road on the right bank of the dam.For the safety of cofferdam and hydraulic structures,the instability of Chenjiazui Landslide mainly affects the flood discharge capacity of dam,navigation safety and power station output.The influence of Qingshiliang Landslide on the project is mainly secondary disaster caused by landslide surge.In addition,an unstable landslide could not only endanger the safety of residents and infrastructure on the slide body,but also affect the flood flow and navigation of the Hanjiang River.The geological hazards have a great degree of harm and great danger.On the basis of the study,engineering measures such as anti-slide pile and stone pedestal draining are suggested in Chen Jiazui Landslide control project,engineering measures such as cutting side load reduction and front guard foot drainage are suggested in Luohongtan and Qingshiliang Landslide control projects.Deformation monitoring should also be adopted in order to eliminate landslide disaster.