东河水位升降对光芒滑坡稳定性的影响

发布时间：2018-05-29 13:43

本文选题：河水位上升 + 河水位下降　；参考：《成都理工大学》2015年硕士论文

【摘要】：三峡库区蓄水后,支流东河受库区高水位影响,导致库岸产生新的地质灾害,影响临近居民居住及财产安全。光芒滑坡位于东河右岸,研究东河水位升降对光芒滑坡稳定性的影响问题具有重要的意义。本文调查了光芒滑坡区的工程地质及水文地质条件,分析了滑坡形成过程及机制,采用定性分析与定量计算相结合的方法,得出了河水位上升及下降情况下不同工况不同时刻光芒滑坡地下水位特征,考虑河水位上升及下降、不同工况、不同时刻,对光芒滑坡的稳定性进行了计算,并对光芒滑坡稳定性的变化规律进行了总结及分析,取得的主要研究成果如下:1.光芒滑坡属于小型土质牵引式滑坡,滑坡总体坡度较陡,滑体物质组分为第四系的粉质粘土夹碎块石,整体结构松散~稍密,稳定性较差,下伏侏罗系中统沙溪庙组泥岩。滑坡区地下水主要由降雨和上升的东河水补给,东河水位升降对滑坡稳定性的影响较大。分析了光芒滑坡区的工程地质条件,该滑坡区不利的地形地貌和岩土特性是形成滑坡的内在因素,而东河水位的升降造成滑坡区地下水流场的变化是诱发滑坡的重要因素。2.东河水位上升与下降对光芒滑坡区地下水流场有较大影响。当河水位上升时,光芒滑坡区地下水流场的变化特征为:坡体内水位随河水位的上升而上升;受岩土体本身性质的影响,单一浸润线呈一定斜率的曲线,且接近临空面斜率较大,不同时刻浸润线随着水位的上升其倾斜程度变化较小,宏观上表现为河水位与坡体内部水位的差值变化较小。当河水位下降时,光芒滑坡区地下水流场的变化特征为:滑坡体内水位随河水位的下降而下降;受岩土体本身性质的影响,单一浸润线是呈一定斜率的曲线,且接近临空面斜率较大,不同时刻浸润线随着水位的下降其倾斜程度变化较小,宏观上表现为临空面处河水位与坡体内部水位的差值变化较小。3.东河水位上升对光芒滑坡稳定性的影响如下:东河水位上升条件下,滑坡体内水位上升滞后于河水位的上升,滑坡的稳定性先降低后增强,且稳定性的变化较小,当河水位由165m上升至169m时,稳定性系数达到最小值,滑坡稳定性最差,随着水位的继续升高,滑坡稳定性系数逐渐增大。河水位上升总体对滑坡稳定性的影响较小,水位上升速度越快,滑坡稳定性略有降低4.东河水位下降对光芒滑坡稳定性的影响如下:东河水位下降条件下,坡体内水位的下降滞后于河水位的下降,滑坡的稳定性逐步降低,且稳定性的变化较大,河水位由175m下降至171m处,滑坡稳定性下降较快,171m后滑坡稳定性下降速度相对较缓,总体上河水位下降对滑坡稳定性的影响较大。
[Abstract]:After the storage of water in the three Gorges Reservoir, the Donghe River, a tributary, is affected by the high water level in the reservoir area, resulting in a new geological hazard on the bank of the reservoir, which affects the residents living nearby and the safety of property. The Guangliang landslide is located on the right bank of the Donghe River. It is of great significance to study the influence of the rise and fall of the Donghe water level on the stability of the Guangliang landslide. This paper investigates the engineering geology and hydrogeological conditions of Guangguang landslide area, analyzes the forming process and mechanism of the landslide, and adopts the method of combining qualitative analysis with quantitative calculation. The characteristics of underground water level of light landslide at different working conditions and different times are obtained under the condition of rising and falling of river water level. The stability of light landslide is calculated at different working conditions and different times considering the rise and fall of river water level. The variation law of the stability of Guangliang landslide is summarized and analyzed. The main research results are as follows: 1. Guang landslide belongs to the small soil traction type landslide with steep overall slope. The material composition of the landslide body is divided into silty clay and clastic rock of Quaternary system, the whole structure is loose ~ slightly dense, the stability is poor, and the mudstone of Shaximiao formation in the Lower Jurassic Middle Series. Groundwater in landslide area is mainly recharged by rainfall and rising Donghe river, and the fluctuation of Donghe water level has a great influence on landslide stability. The engineering geological conditions of Guangguang landslide area are analyzed. The unfavorable landform and geomorphology and geotechnical characteristics of the landslide area are the internal factors to form the landslide, and the change of groundwater flow field in the landslide area caused by the rise and fall of the Donghe water level is the important factor that induces the landslide. The rise and fall of the East River level have a great influence on the groundwater flow field in the Guangliang landslide area. When the water level rises, the variation characteristics of groundwater flow field in Guangliang landslide area are as follows: the water level in slope increases with the increase of river level, and the single infiltration line is a slope curve affected by the nature of rock and soil. The slope near the empty surface is larger, and the slope degree of the infiltration line varies slightly with the increase of water level at different times, and the difference between the river level and the water level in the slope is small in macroscopic view. When the water level of the river drops, the variation characteristics of groundwater flow field in Guangliang landslide area are as follows: the water level in the landslide decreases with the decrease of the river level, and the single infiltration line is a curve with a certain slope due to the nature of the rock and soil. The slope near the goaf surface is larger, and the slope degree of the infiltration line changes slightly with the decrease of the water level at different times, and the difference between the river level near the empty surface and the water level in the slope is small. 3 in macroscopically, the difference between the water level near the empty surface and the water level in the body of the slope is small. The influence of rising of Dongjiang river level on the stability of Guangliang landslide is as follows: under the condition of rising level of Dongjiang river, the rise of water level in landslide lags behind that of river level, and the stability of landslide decreases first and then increases, and the change of stability is small. When the water level rises from 165m to 169m, the stability coefficient reaches the minimum, and the landslide stability is the worst. With the increase of water level, the landslide stability coefficient increases gradually. The increase of water level has little effect on landslide stability. The faster the water level rises, the lower the landslide stability is. The influence of Donghe water level decline on the stability of Guangliang landslide is as follows: under the condition of the Donghe water level falling, the fall of the water level in the slope lags behind that of the river level, and the stability of the landslide decreases gradually, and the stability changes greatly. When the water level of the river drops from 175m to 171m, the stability of the landslide decreases more quickly, and the stability of the landslide decreases relatively slowly after 171m. In general, the drop of the level of the river has a great influence on the stability of the landslide.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

【参考文献】