仰斜式排水孔在滑坡治理中的应用研究和影响因素分析

发布时间：2018-01-31 23:27

本文关键词： 滑坡仰斜式排水孔渗流计算稳定性　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国社会主义建设的进展,在公路工程、铁路工程、采矿工程、水电站工程等项目建设中经常需要对危险滑坡进行处治,对滑坡治理程度的好坏往往决定着项目的进展和经济成本。因而,通过深入系统地探究滑坡的成因、作用机理以及排水条件下滑坡渗流场和稳定性的变化情况,了解影响滑坡作用的主要因素和形成规律,为今后公路等基础设施建设中遇到的滑坡预防、稳定性评价以及治理设计提供一定的参考。本文主要研究内容及结论有:①在对基于正交试验法的多因素敏感性分析理论和方法的分析研究的基础上,针对滑坡的主要影响因素,本文主要列举土体重度、粘聚力、内摩擦角、孔隙压力比、水头高度这五个因素,运用多因素正交试验法进行了敏感性分析。得到结论:滑坡稳定性对内摩擦角的变化最为敏感,其次分别为粘聚力,水头高度,孔隙压力比,对土体重度的变化最不敏感。②分析了地下水影响滑坡稳定性的作用机理,结合饱和-非饱和渗流的基本理论,建立了滑坡渗流分析和稳定性计算的模型,选取了滑坡土体的特性参数、渗流计算的参数和边界条件,系统地分析了是否布设排水孔以及布设仰斜式排水孔在不同孔长、孔径、仰角的情况下滑坡的渗流场和稳定性变化。得出结论:布设排水孔能够对滑坡体起到明显的排水降压作用,增强滑坡整体稳定性;仰斜式排水孔的孔长越长,排水降压效果越好,影响范围越大,但也要结合滑坡治理所需降低水位的范围和实际的地质条件来综合确定;仰斜式排水孔的排水效果对仰角变化不太敏感,必须根据实际的滑坡体自由水面位置来确定,推荐仰角θ取值在6°~10°范围较为合理;仰斜式排水孔的排水效果对孔径变化最不敏感,孔径太大或太小都不能达到很好的排水降压效果,推荐孔径D为0.1m左右比较合适。③结合国内外关于仰斜式排水孔的发展历程和现状,根据关于仰斜式排水孔相关的规定及其施工机具和施工工艺,提出了一些行之有效的优化建议。如将仰斜式排水孔的前端部分设置成上部50%透水,下部50%不透水;仰斜式排水孔孔内设置略小于排水孔的PVC或PE渗水管;孔口进行灌浆和防晒处理,在靠近出水口60cm长度范围内用粘性土或者止水材料堵塞钻孔与排水管之间的空隙;仰斜式排水孔孔口以下坡面应该做加固处理,防止冲刷坡面;定期对排水孔进行清理,防止排水孔淤塞等。
[Abstract]:With the progress of socialist construction in China, it is often necessary to treat dangerous landslides in the construction of highway, railway, mining and hydropower projects. The degree of landslide treatment often determines the progress and economic cost of the project. Therefore, through in-depth and systematic exploration of the cause of landslide, the mechanism of action and the landslide seepage field and stability changes under drainage conditions. To understand the main factors affecting the landslide and the formation of the law for the future road and other infrastructure construction encountered landslide prevention. Stability evaluation and governance design provide a certain reference. The main contents and conclusions of this paper are: 1 on the basis of the analysis of the theory and method of multi-factor sensitivity analysis based on orthogonal test. Aiming at the main influencing factors of landslide, this paper mainly enumerates five factors: soil mass, cohesion, internal friction angle, pore pressure ratio and water head height. The sensitivity analysis was carried out by means of multi-factor orthogonal test. It is concluded that the stability of landslide is the most sensitive to the change of internal friction angle, followed by cohesion, water head height and pore pressure ratio. Based on the basic theory of saturated-unsaturated seepage, the model of landslide seepage analysis and stability calculation is established. The characteristic parameters of landslide soil, the parameters of seepage calculation and boundary conditions are selected to analyze systematically whether the drainage holes are installed or not and whether the inclined drainage holes are arranged in different hole length and aperture. In the case of elevation angle, the seepage field and stability of the landslide are changed. It is concluded that the placement of drainage holes can play an obvious role in drainage and pressure reduction of the landslide and enhance the overall stability of the landslide. The longer the orifice is, the better the effect of drainage pressure reduction is and the larger the influence range is, but it is also necessary to determine comprehensively the range of lowering water level and the actual geological conditions needed for landslide treatment. The drainage effect of the tilted drainage hole is not sensitive to the elevation angle change, it must be determined according to the actual free water surface position of the landslide body, and the recommended elevation angle 胃 value is reasonable in the range of 6 掳~ 10 掳. The drainage effect of the inclined drainage hole is the most insensitive to the change of the pore diameter. Too large or too small aperture can not achieve a good drainage pressure reduction effect. The recommended aperture D is about 0.1 m. 3 combined with the development history and present situation of the tilted drainage hole at home and abroad, according to the relevant regulations, construction equipment and construction technology. Some effective optimization suggestions are put forward, such as setting the front part of the tilted drainage hole to the upper 50% percolation and the lower 50% impervious; A PVC or PE seepage pipe is arranged in the upside-inclined drainage hole which is slightly smaller than the drainage hole; Grouting and sunscreen are carried out at the orifice, and the gap between the borehole and the drain pipe is blocked by clay or watertight material within the length of 60cm near the outlet. The slope below the orifice of the drainage hole should be strengthened so as to prevent the slope from scouring. Regular drainage hole cleaning, to prevent drainage hole blockage and so on.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22;TU753.8

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