巴中黄石盘水库库区黄角树古滑坡前缘变形体稳定性分析及堵江预测研究

发布时间：2018-03-24 09:21

本文选题：库岸边坡　切入点：水位升降　出处：《成都理工大学》2017年硕士论文

【摘要】：拟建巴中黄石盘水库库区位于巴河支流——恩阳河中游河段,黄角树古滑坡位于恩阳河左岸,长约390m,宽约290m,面积约为10.1×104m2,堆积体平均厚度约19m,古滑体方量约192×104m3,滑动方向为182°。汶川地震后地表产生新的裂隙,在雨季过后裂隙不断延伸和拉开,变形体新的变形方向为244°,长约190m,宽约310m,面积约为4.8×104m2,平均厚度约9m,变形体方量约43×104m3。暴雨工况下,前缘变形体有明显的变形,因此对水库运行时分析其稳定性是必要的,对其破坏后的堵江高度进行预测,对保障水库正常运营及防灾减灾具有十分重要意义。论文在调查黄角树古滑坡堆积体的基础上,查阅资料并对滑坡的工程地质条件、形成及复活机制以及前缘变形体变形的影响因素进行分析,总结地下水对前缘变形体的作用机制,研究滑带土力学参数的取值方式,用GEO-Studio软件分析评价其稳定性,用经验法和PFC2D颗粒流软件预测失稳后形成的堰塞坝高度,分析堵江对黄石盘水库以及整个区域带来的危害和造成的影响。针对川东红层块碎石土堆积物的堵江预测问题,具有参考和借鉴意义。通过本文的研究,得到以下主要结论:(1)黄角树古滑坡是一个经过多次滑移且滑坡体物质堆积差异性较大的古滑坡,滑面产状约为182°∠9°;前缘变形体的变形方向为244°,潜在滑面位于古滑面之上,影响前缘变形体形成的因素主要为岩土体膨胀性,坡体结构,降雨,河水侧蚀,人类工程活动和地震。(2)库水位升降改变前缘变形体的岩土体的含水量,使岩土体进入干湿循环状态,造成滑面的力学强度参数降低;静水压力、动水压力增加和超孔隙水压力出现,对基质吸力和底滑面的摩擦力产生直接的影响。(3)古滑坡在所有工况下均是稳定的,前缘变形体则在库水位1m/d上升、1m/d下降和13m/d下降工况下会发生破坏,不是整体破坏,而是各区域分块先后下滑。(4)PFC2D颗粒流方法预测,库水位13m/d下降时,前缘变形体区造成的堵江高度(堰塞坝最低高程)为353米,属于不完全堵江,但已完全堵塞原河道。(5)堵江后河水对右岸的侧蚀强度增加,累进破坏及库岸的再造会形成新的滑坡,进一步形成完全堵江,引发上游回水淹没,下游部分断流,涌浪,溃决洪水,岸坡改造,再次堵江,水源污染等一系列次生灾害和环境效应。
[Abstract]:The proposed reservoir area of Huangshipan Reservoir in Bazhong is located in the middle reaches of the Buhe tributary-Enyang River, and the Huangjiaoshu landslide is located on the left bank of the Enyang River. The length is about 390m, the width is about 290m, the area is about 10.1 脳 104m2, the average thickness of the accumulation body is about 19m, the volume of paleo-slip body is about 192 脳 104m3.The slip direction is 182 掳. After the Wenchuan earthquake, new fissures appear on the surface, which continue to extend and open after the rainy season. The new deformation direction is 244 掳, the length is about 190m, the width is about 310m, the area is about 4.8 脳 104m2, the average thickness is about 9m, and the deformational square is about 43 脳 104m3.The deformation of the front edge deformation is obvious under the heavy rain condition, so it is necessary to analyze the stability of the reservoir during operation. It is very important to predict the height of blocking the river after its destruction to ensure the normal operation of the reservoir and to prevent and reduce the disasters. On the basis of investigating the accumulation body of Huangjiaoshu ancient landslide, the paper consults the data and gives the engineering geological conditions of the landslide. The forming and reviving mechanism and the influencing factors of the deformation of the leading deformable body are analyzed, the mechanism of groundwater acting on the leading deformable body is summarized, the method of selecting the mechanical parameters of the sliding zone soil is studied, and the stability of the landslide zone is analyzed and evaluated by GEO-Studio software. Using the empirical method and PFC2D particle flow software to predict the height of dam and Weir after instability, the harm and influence of river plugging on Huangshipan reservoir and the whole area are analyzed. Through the research in this paper, the main conclusions are as follows: 1) Huangjiao Shu ancient landslide is an ancient landslide with many slippages and great difference in material accumulation. The deformation direction of the front deformable body is 244 掳. The potential slip surface is located above the paleo-slip surface. The main factors influencing the formation of the front deformation body are the expansibility of the rock and soil, the structure of the slope body, the rainfall, the side erosion of the river water, etc. Human engineering activities and earthquake. 2) the water level of reservoir changes the water content of the rock and soil in the front deformable body, which makes the rock and soil enter into the dry and wet cycle state, resulting in the decrease of the mechanical strength parameters of the sliding surface, the hydrostatic pressure, the hydrostatic pressure, the hydrostatic pressure, The increase of hydrodynamic pressure and the appearance of excess pore water pressure have a direct effect on the matrix suction and the friction force on the bottom sliding surface. The leading deformable body will destroy under the condition of 1m/d rising 1 m / d and 13m/d decreasing. It is not the whole failure, but the method of particle flow prediction, when the water level of the reservoir drops when the 13m/d level drops. The height of river plugging (the lowest height of dam and Weir) caused by the deformation of the front edge is 353 meters, which is not complete, but the original river has been completely blocked. After blocking the river, the intensity of side erosion of the river to the right bank is increased. Progressive destruction and reengineering of the reservoir banks will result in new landslides, further blocking the river completely, causing upstream backwater inundation, partial disconnection of downstream flows, surges, outburst floods, bank slope reconstruction, and reblocking of the river. Water pollution and a series of secondary disasters and environmental effects.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22;TV223

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