贵州某机场高填方边坡稳定性研究

发布时间：2018-06-02 01:53

本文选题：机场高填 + 方边坡稳定性　；参考：《成都理工大学》2017年硕士论文

【摘要】：拟建机场位于贵州省威宁县内,场区内地层主要由第四系残破积物(Q4el+dl)、二叠系下统梁山组(P1l)以及上石炭统马坪群组(C3mp)组成,其中二叠系梁山组(P1l)岩性为中厚层砂岩夹层薄层状的炭质页岩、泥岩,属于硬岩夹软岩的组合类型。受威宁背斜控制,区内边坡为顺层结构,自然状态下发育的主要地质灾害为滑坡。该拟建机场设计填方高度最高达66m,平均填方高度大于在30m,在此边坡上进行填方,边坡的稳定性问题严重。因此,本文以高填方边坡为研究对象,研究此类高填方边坡的稳定性,对该类型机场高填方边坡的稳定性分析具有重要的工程意义。为了研究该机场高填方边坡的稳定性,首先,在查明研究区自然边坡的地质条件、岩土体结构和力学特征以及变形破坏特征的基础上,分析自然边坡的变形破坏机制。然后,利用自然边坡的变形破坏机制,通过地质分析,分析了高填方边坡的稳定性影响因素,进而探讨了高填方边坡的变形破坏模式。最后,考虑天然、暴雨和地震三种工况,应用FLAC-3D分析整个填方体边坡的稳定性,再采用极限平衡法分析三条典型剖面上不同填方边坡的稳定性,并在此基础上,对该机场边坡提出针对性的治理防治措施建议。通过上述内容的研究得出以下结论:(1)自然状态下区内发育滑坡3处,不稳定斜坡1处,规模为中小型。其发育受到地形地貌、地层岩性、地质构造、坡体结构、降雨和地震等多种因素控制,空间分布相对集中,主要发育在I#沟流域,以及IV#沟左侧顺层斜坡中。其中斜坡自然坡度在14~27°,坡面呈现“陡—缓—陡”的形态特征,具有以泥岩和炭质页岩为主的软弱夹层,在临空条件较好的顺层斜坡中极为发育。(2)研究区内滑坡、不稳定斜坡的坡体内部岩层为中厚层砂岩夹薄层状泥岩、炭质页岩,砂岩厚度0.3~0.5m,泥岩、炭质页岩层厚小于0.1m,为硬岩夹软岩的组合类型,岩层倾角由陡变缓,软弱夹层在坡体前缘并未剪出。砂岩和泥岩、炭质页岩间存在透水性的差异,雨水透过砂岩层入渗到泥岩等阻水层面,造软弱岩层的软化。其自然边坡的变形破坏机制为滑移—弯曲。(3)结合自然边坡的坡体结构、地形地貌和变形破坏机制分析得出,影响高填方边坡稳定性的因数有四种:一是自然边坡上植被的发育特征;二是第四系覆盖层的分布特征;三是自然边坡发育的地形地貌;四是边坡的坡体结构类型。结合影响因数分析高填方边坡的主要破坏方式分为五种:一是沿自然边坡坡体表面发生的变形破坏;二是沿着第四系覆盖层内的变形破坏;三是沿着基覆界面的变形破坏;四种是沿着原有滑面的破坏;五是沿着软弱结构面的深层次破坏。(4)对高填方边坡的稳定性进行FLAC-3D数值模拟分析:天然工况下,填方体的整体位移较小,主要位移区分布在I#沟上游右侧不稳定斜坡部位,填方体上分布有零星的塑性变形,天然工况下填方边坡稳定较好;暴雨工况下,填方体的位移增大,塑性破坏主要集中在软弱结构面的位置,雨水入渗至软弱结构面,造成软弱结构面软化,从而造成填方边坡的整体失稳;地震工况下,填方体位移数值变化和降雨工况下相差不大,塑性变形分布在整个填方体上,塑性破坏区集中在软弱结构面附近,地震作用下高填方边坡出现变形破坏。(5)采用极限平衡法,分析了三条典型剖面上不同填方边坡的稳定性,其结果表明。高填方边坡在自然状态下稳定性不同,剖面I-I’、剖面II-II’和剖面III-III’上填方边坡稳定性较好,高填方边坡处于稳定状态;在降雨和地震的作用下,受到软弱结构面和已有滑面的影响,三条剖面上的填方边坡均处于基本稳定~欠稳定状态。(6)结合边坡稳定性评价结果,对高填方边坡提出了有针对性的治理措施建议:根据高填方边坡的稳定性情况进行工程治理处理,总体上从原地基的处理、填方体的处理及排水方法着手。通过对典型剖面的治理工程措施检验效果来看,在不清除坡表层覆盖层的情况下,抗滑桩是最为有效的治理措施。
[Abstract]:The proposed airport is located in Weining County, Guizhou province. The interior layer of the field is mainly composed of the Quaternary broken deposits (Q4el+dl), the Permian lower Liangshan formation (P1l) and the upper Carboniferous Ma Ping group (C3mp), and the Permian Liangshan formation (P1l) lithology is a thin layer of thin layer of carbonaceous shale in the middle and thick layer sandstone, and the mudstone belongs to the combination type of hard rock soft rock. The Weining anticline is controlled by the slope of the area. The main geological hazard developed under natural condition is landslide. The height of the proposed airport design is up to 66m, the height of the average fill is greater than that of 30m. The slope is filled on the slope, and the stability of the slope is serious. Therefore, this paper takes the high fill slope as the research object and studies this kind of high grade. The stability of the fill slope is of great engineering significance to the stability analysis of the high fill slope of this type of airport. In order to study the stability of the high fill slope of the airport, first of all, on the basis of finding out the geological conditions of the natural slope in the study area, the structure and mechanical characteristics of the rock and soil, and the characteristics of the deformation failure, the change of the natural slope is analyzed. Then, using the deformation and failure mechanism of the natural slope, through the geological analysis, the influence factors of the stability of the high fill slope are analyzed, and the deformation and failure mode of the high fill slope is discussed. Finally, the stability of the whole fill slope is analyzed with the natural, rainstorm and earthquake, and FLAC-3D is used to analyze the stability of the whole fill slope, and then the limit is adopted. The equilibrium method is used to analyze the stability of the different fill slopes on three typical sections, and on this basis, some countermeasures are proposed for the prevention and control of the slope of the airport. Through the study of the above contents, the following conclusions are drawn: (1) 3 landslides are developed in the natural state and 1 of the unstable slopes, and the scale is medium and small. The appearance, lithology, geological structure, slope structure, rainfall and earthquake are controlled by many factors, and the spatial distribution is relatively concentrated, mainly developed in the I# gully basin and the left parcen slope of IV# gully. The slope natural slope is 14~27 degrees, and the slope surface presents "steep to steep" morphological characteristics, and has the weak clips mainly of mudstone and carbonaceous shale. The layer is developed very well in the bedding slope with better conditions. (2) the slope in the study area is the slope of the unstable slope. The inner rock of the unstable slope is a thin layer of thin sandstone with medium and thick sandstone, the thickness of the carbonaceous shale, the sandstone thickness 0.3~0.5m, the mudstone and the carbonaceous shale is less than 0.1M, which is a combination of hard rock and soft rock, the dip angle of the rock layer is slowed down and the soft intercalation is in the slope. The front edge of the body has not been cut out. There is a permeable difference between the sandstone and mudstone and the carbonaceous shale. The rain water through the sandstone layer infiltrates into the mudstone and other water resistance layers, and the soft rock is softened. The deformation and failure mechanism of the natural slope is slipping and bending. (3) the analysis of the slope structure of the natural slope, the topography and the deformation failure mechanism analysis, and the influence of the deformation and failure mechanism. There are four factors for the stability of high fill slope: one is the characteristics of vegetation development on the natural slope; two is the distribution characteristic of the Quaternary cover layer; three is the topography and geomorphology of the natural slope development; four is the slope structure type of the slope. In combination with the influence factor analysis, the main failure modes of the high fill slope are divided into five kinds: one is the natural slope slope. Deformation damage occurred on the surface of the body; two is deformation and failure along the Quaternary cover layer; three is the deformation and failure along the base cladding interface; the four is along the original sliding surface damage; five is along the weak structural surface deep damage. (4) the stability of the high fill slope FLAC-3D numerical simulation analysis: natural conditions, fill the whole body of the whole The displacement area is smaller and the main displacement area is distributed in the unstable slope part of the right side of the I# ditch. The plastic deformation is scattered on the fill body, the filling slope is stable under the natural condition, the displacement of the fill increases and the plastic damage is mainly concentrated on the weak structural plane under the heavy rain condition, and the rain is infiltrated into the weak structural surface and causes weakness. The structure surface is softened, which causes the overall instability of the fill slope; under the earthquake condition, the displacement of the filling position is not very different from the rainfall condition, the plastic deformation is distributed on the whole fill, the plastic failure area is concentrated near the weak structural surface, and the high fill side slope under the earthquake is deformed and destroyed. (5) the limit equilibrium method is used to analyze the deformation. The stability of different fill slopes on the three typical sections shows that the stability of the high fill slope in the natural state is different, the section I-I ', the section II-II' and the section III-III 'fill slope is stable, the high fill slope is in the stable state, and under the action of rainfall and ground earthquake, it is subjected to the weak structural surface and the existing sliding surface. The influence of the three sections of the fill slope is in the basic stable and unstable state. (6) combined with the stability evaluation results of slope, the high fill slope of the treatment measures proposed: according to the stability of high fill slope stability of engineering treatment, in general, from the original foundation treatment, fill the treatment and drainage square. According to the test results of the treatment measures of typical sections, the anti slide pile is the most effective control measure without removing the cover layer of the slope surface.
【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】：V351.1;TU43

【参考文献】