渭玉高速公路沿线滑坡发育特征及稳定性研究

发布时间：2018-01-04 01:06

本文关键词：渭玉高速公路沿线滑坡发育特征及稳定性研究　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着“西部大开发”战略的实施,西部地区高速公路里程显著增长,完善了西部地区路网结构、加强了区域经济联系、改善了运输环境,促进了地方经济发展和社会进步。但近年来,西部地区高速公路的负效应也日益突出,滑坡、崩塌等地质灾害对交通工程建设、公路安全运营以及区域人民财产安全产生了不同程度的危害,因此对公路地质灾害的研究具有重要意义。本文以渭玉高速公路沿线25处滑坡为研究对象,分析其发育特征、影响因素、形成机理,评价其稳定性,具有一定的应用价值,取得了以下结论:(1)沿线滑坡发育特征:从滑坡厚度、规模、形成时代及物质组成分析得出,滑坡以新滑坡为主,中厚层、中型滑坡最为发育,可分为黄土层内型滑坡滑坡和黄土-基岩型滑坡;平面形态可分为扇形、舌形、叠瓦形以及双头M形四种类型;黄土层内型滑坡,其剖面形态以凹形为主,而黄土-基岩型滑坡以阶梯状为主;外形特征滑坡宽度长度之比以1-1.6之间居多;黄土层内型滑坡其边界特征表现为剪出口位置相对较高,而黄土-基岩型滑坡剪出口位置较低;黄土层内型滑坡变形特征呈现出滑带后部多呈近似直线,而黄土-基岩型滑坡滑带整体多呈圆弧形;黄土层内型滑坡运动特征以抛出解体型为主,而黄土-基岩型滑坡以错动滑出型为主。(2)沿线影响滑坡发育的主要因素包括大气降水、坡度、地表水以及地层岩性;次要因素为坡高、工程建设、地下水、地貌、新构造运动、农业灌溉、构造格局、外部荷载以及断裂;综合分析了沿线滑坡形成原因,即地层岩性是滑坡形成的重要内因和物质基础,地形地貌是空间因素,雨水是动力因素和诱发因素;提出了沿线滑坡的蠕变-拉裂运动机理,分为蠕动变形,蠕动挤压,滑动加速,拉裂下滑四个阶段。(3)对沿线滑坡进行了稳定性分析与评价:黄土层内型滑坡在天然状态下以基本稳定状态为主,在饱水状态下以欠稳定状态为主;黄土-基岩型滑坡在天然和饱水状态下以稳定状态为主;在地震状态下沿线滑坡以不稳定状态为主;降雨使沿线滑坡的稳定系数平均降低了 8.23%;地震使沿线滑坡的稳定系数平均降低了 21.18%;研究区按稳定性可分为稳定-基本稳定区和欠稳定区。
[Abstract]:With the implementation of the strategy of "developing the West", the highway mileage in the western region has increased significantly, the road network structure in the western region has been improved, regional economic ties have been strengthened, and the transportation environment has been improved. Promote the local economic development and social progress, but in recent years, the negative effects of highway in the western region are increasingly prominent, landslide, collapse and other geological disasters on traffic engineering construction. Highway safety operation and regional people's property safety have different degrees of harm, so the study of highway geological hazards is of great significance. This paper takes 25 landslides along Wei-Yu expressway as the research object. Analysis of its development characteristics, influencing factors, formation mechanism, evaluation of its stability, has certain application value, obtained the following conclusions along the landslide development characteristics: from the landslide thickness, scale. The formation time and material composition analysis show that the landslide is mainly new landslide, medium thick layer, medium landslide is the most developed, can be divided into loess inside landslide and loess-bedrock type landslide; The plane shape can be divided into four types: sector shape, tongue shape, imbricate shape and double head M shape. The profile of loess landslide is mainly concave, while that of loess bedrock landslide is ladder. The ratio of the width and length of the landslide is mostly between 1-1.6; The boundary characteristic of loess landslide is that the location of shear exit is relatively high, but the location of loess bedrock landslide is lower. The deformation characteristics of loess landslide show that the back part of the slip zone is almost straight, while the loess-bedrock landslide slide zone is mostly circular arc. The characteristics of landslide movement in loess layer are mainly disintegrating type, while that of loess-bedrock landslide is mainly staggered slip type. The main factors that influence the development of landslide along the loess layer include precipitation and slope. Surface water and stratigraphic lithology; The secondary factors are slope height, engineering construction, groundwater, geomorphology, neotectonic movement, agricultural irrigation, structural pattern, external loads and faults; The formation reason of landslide along the route is analyzed synthetically, that is, stratigraphic lithology is the important internal cause and material foundation of landslide formation, landform is space factor, Rain Water is dynamic factor and inductive factor. The creep-tensile movement mechanism of landslide along the line is put forward, which includes creep deformation, creep extrusion and sliding acceleration. The stability of landslide along the line is analyzed and evaluated in four stages, I. e., the basic stable state in the natural state and the unsteady state in the saturated state. Loess-bedrock landslide is mainly stable in natural and saturated state. Under the earthquake condition, the landslide along the route is mainly unstable. The stability coefficient of landslide along the line was reduced by 8.23 by rainfall. The stability coefficient of landslide along the line was reduced by 21.18% after the earthquake. According to the stability, the study area can be divided into stable-basic stable region and understable region.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U412.22;P642.22

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