【作者】 牛红梅；

【导师】 吕小平；

【作者基本信息】 西南交通大学 ， 地质工程， 2008， 硕士

【摘要】 瓦屋山水电站环库区移民场地是洪雅县瓦屋山水电站工程移民迁建的重点地区,也是库区内边坡地质灾害多发地区。边坡在复杂地质环境、大规模的工程活动及暴雨等条件下,可能会发生变形,甚至失稳破坏。一旦失稳,将阻断交通,严重威胁人民的生命、财产安全。同时危及移民工程的建设,影响瓦屋山水电站工程移民工作进度。该场地边坡多为第四系冰水堆积、冰水湖堆积层边坡,具有特殊的工程性质。为加快瓦屋山水电站环库区移民场地地质灾害治理工作的进度,确保库区移民搬迁,对该区边坡灾害进行综合治理已刻不容缓。边坡稳定性分析和治理研究是边坡工程研究的核心问题。本文针对该地区边坡的特殊地质、环境与工程条件,在广泛了解相关资料的基础上,深入系统的分析了该地区地质灾害体的成因及现状。根据边坡的特征,运用现场调查、实验室土工试验、数值计算、理论分析和方案比选等方法,并结合具体边坡实例,对该地区边坡的综合治理进行了研究。其主要内容和成果包括:(1)本次研究以野外调查为主要手段,对研究区内所有灾点逐一进行现场调查,对严重的灾害点进行现场取样,以便进行土工试验,以此来确定场地岩土的物理、力学、水理性质。并利用现有的各种相关资料,从整体上把握该区边坡的工程地质条件,并提出影响边坡稳定性的因素。(2)在研究区,降雨是边坡稳定性的主要影响因素之一。在非饱和土坡稳定性验算中,由于非饱和土体中基质吸力对边坡稳定性有利,故不考虑孔隙水压力的影响。然而降雨使土体含水量增加,导致粘聚力、内摩擦角和基质吸力降低,从而在整体上降低了土体的抗剪强度;降雨使非饱和土坡重度增加,下滑力增大;雨水入渗产生渗透力等这些因素都对边坡的稳定性不利。根据调查分析,降雨量、地下水位与边坡的稳定性之间都存在着密切的关系,但以往人们对这种关系的认识和理解仍很不充分。论文从分析降雨诱发边坡失稳的原因入手,研究雨水入渗引发滑坡的物理过程,建立定量的分析模型。根据建立的分析模型,研究降雨与边坡稳定性之间的关系。结果表明:对稳定性安全系数(不考虑降雨作用时)较大的边坡,滑坡主要发生在降雨初期,降雨引起局部稳定性降低;对稳定性安全系数(不考虑降雨作用时)较小的边坡,既可能在降雨初期发生局部失稳,也可能在长期降雨作用下发生整体失稳。(3)在了解研究区边坡防治的基本原则、方法及综合治理措施的基础上,结合具体滑坡实例从预防与治理两方面出发,研究滑坡综合治理措施。提出了三种综合治理的方案,并对各个方案的特点和适宜性进行了分析,通过方案比选,决定采用方案二抗滑桩与截排水相结合为滑坡治理的综合治理方案。更多还原

【Abstract】 The area around Wawu mountain hydropower station in Hongya County is one of the key areas which have to emigrate their residents due to the construction of Wawu mountain hydropower station, and at the same time which are slops-stricken areas. Many slops may be happened deformation, even instability damage , resulting from inducements of complex geological environment,large-scal projects construction and long-time raining, will block traffic, seriously threaten the properties and lives of its local people , as well as the progress of emigration there once it loses its stability. Many slops in this site are Quaternary system ice-water accumulational slops or ice-lake accumulational slops which have special engineering characteristic. So to speed up the progress of dealing with geological disasters in Wawu mountain hydropower station area and guarantee smooth emigration there, comprehensively tackling slops in this area can’t be delayed any more.Slope stability analysis and treatment study are the core problem to slope engineering research. This paper has systematically analyzed geologically disastrous body’s current situation and its contributing factors based on in-depth understanding its special geology, environment, engineering conditions and related materials in this area. According to the features of slops in this area, using scene investigation, laboratory soil test, numerical calculation, the theoretical analysis and project selection, and combining with specific examples of slope, there is a study on the comprehensive treatment of the area slope. The main contents and results attained are as follows:(1) Principal means of the research is field investigation. All the dangerous points in study area are investigated one by one, and the serious dangerous points need field sampling for soil tests, in order to determine the field geotechnical physical properties, mechanical properties, and water-physical properties . The paper grasps the slope’s engineering geological conditions by using all relevant information existing now, and puts forward to the influence factors of slope stability.(2) In study area, the rainfall is one of the main influence factors of the stability of slope.The stability checking computations in slight saturate slope doesn’t consider the influence of the water pressure strength of hole, because it isuseful to the stability of slope there is suction in saturate soil. But rainfall make containing water in soil body increase, glue and gather strength, interior angle of friction and suction reduce, thus reduce resist shearing force of soil body at whole; and make weight of slight saturate slope increase, it bring glide force up; at the same time, produce scepage force. These factors are disadvantageous to stability of slope. According to investigating and analysis, rainfall, water table have close relation with stability of slope, but people were still very insufficient to understanding this kind of relation in the past. Thesis analyze the causes that rainfall bring out slope lose, set up quantitative analysis model. According to the analysis model, study the relation between rainfall and the slope stability. The result shows, that the slope having high stability safety factor, may lose mainly part stability in the initial stage of rainfall, and that the slope having low stability safety factor, may lose part stability on the initial stage of rainfall, or may lose wholly stability after rainfall for a long time too.(3) On the basis of understanding the basic principle、methods and comprehensive control measures of slope control in study area, this paper researched landslide comprehensive program of public order measure from prevention and treatment aspect.Three kinds of comprehensive schemes of public order are proposed and analyzed features and adaptation of each one respectively. In the end, it clarified the project combined anti-slide with drainage and interception system is the best method of treatment in the landslide by comparing them .更多还原