紫坪铺库区漩口滑坡监测及稳定性分析

发布时间：2018-02-16 16:36

本文关键词： 紫坪铺库区漩口滑坡滑坡监测数值模拟稳定性分析　出处：《中国地质大学（北京）》2014年硕士论文　论文类型：学位论文

【摘要】：紫坪铺水库是国家重要的水利枢纽工程,自2005年建成蓄水以来,库岸边坡开始出现不稳定变形迹象,2008汶川地震诱发了一系列库岸边坡崩塌、滑坡地质灾害。漩口滑坡位于紫坪铺库区西侧岷江与寿江交汇处,滑坡岩性为三叠系须家河组顺层粉质砂岩、页岩夹煤线,方量约150×104m3。汶川地震漩口滑坡出现变形加速现象,有发生失稳滑动的趋势。鉴于漩口滑坡有潜在堵江、形成水库涌浪及埋覆G213国道在建白云顶隧道的危险性,本文对漩口滑坡所在位置的降雨量和库水位以及滑坡地表位移、深部位移、地下水位展开监测,并借助GeoStudio SEEP/W模块和SLOPE/W模块对该滑坡的渗流特性和稳定性进一步研究,取得了以下认识和成果： (1)自2012年7月至2014年2月,地表累积变形达360mm,滑面位于坡面以下18-32m,滑动倾角约为180,具有扭转趋势。坡面中上部已经形成了显著的拉裂,前缘出现局部失稳滑塌,整体稳定性较差。 (2)降雨入渗量方面,在考虑植物截留量、叶面蒸发量以及降雨径流量的情况下确定了漩口滑坡坡面日降雨入渗量约为8×104m/d。 (3)库水位升降过程中安全系数存在极值现象,库水位上升过程中出现极大值、下降过程中出现极小值,极值大小及出现时刻与库水位高度及上升或下降速度有关。库水位下降速度越快安全系数越小,库水位下降过程中渗流速度在前缘有垂直坡体向外的分量,不利于坡体稳定。 (4)构造节理裂隙、裂缝等的发育为降雨入渗提供了良好通道,是影响漩口滑坡失稳的主要原因之一。 (5)库水位下降与暴雨的结合是漩口滑坡发生滑动的最不利工况。应该合理安排水库的蓄排水,避免过快的放水(尤其是在雨季)。
[Abstract]:Zipingpu Reservoir is an important water conservancy project in China. Since its completion in 2005, the bank slope of the reservoir began to show signs of unstable deformation. The 2008 Wenchuan earthquake induced a series of bank slopes to collapse. The landslide is located at the junction of Minjiang River and Shoujiang River on the west side of Zipingpu Reservoir area. The landslide lithology is the bedding silty sandstone of the Xujiahe formation of Triassic, the shale intercalated coal line, the volume of which is about 150 脳 104m3.The Waikou landslide of Wenchuan earthquake appears the phenomenon of acceleration of deformation. There is a tendency of instability and sliding. In view of the potential river plugging in the Waikou landslide and the danger of reservoir surge and the construction of Baiyun top tunnel under construction of the G213 National Road, the rainfall, reservoir water level and landslide surface displacement in the location of the Waikou landslide are discussed in this paper. The deep displacement and groundwater level are monitored, and the seepage characteristics and stability of the landslide are further studied with the help of GeoStudio SEEP/W module and SLOPE/W module. The following results have been obtained:. From July 2012 to February 2014, the accumulated deformation of the surface reached 360 mm, the slip surface was located below the slope surface 18-32 m, the slip inclination was about 180, and the slope had a torsional trend. The upper and middle part of the slope had formed a significant tension crack, and the local unstable slide appeared in the front edge. The overall stability is poor. (2) in the aspect of rainfall infiltration, the daily rainfall infiltration on the slope of Wingkou landslide is about 8 脳 10 ~ 4 m / d considering plant interception, leaf evaporation and rainfall runoff. (3) in the process of water level rise and fall, the safety factor has extreme value phenomenon, the maximum value appears in the process of water level rising, and the minimum value appears in the process of falling. The maximum value and appearance time are related to the height of reservoir water level and the speed of rising or falling. The faster the water level drops, the smaller the safety coefficient is, and the percolation velocity has the component of vertical slope body in the process of reservoir water level falling, which is not conducive to the stability of slope body. 4) the development of structural joints, fractures and so on provides a good channel for rainfall infiltration, which is one of the main reasons that affect the instability of the Whirlangkou landslide. (5) the combination of falling reservoir water level and heavy rain is the most unfavorable condition for landslide sliding in Waikou. The reservoir drainage should be reasonably arranged to avoid excessive discharge (especially in the rainy season).
【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P642.22;TV221.2

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