连接式土工袋结构性能研究

发布时间：2018-06-30 02:50

本文选题：连接式土工袋 + 挡土墙　；参考：《重庆大学》2016年硕士论文

【摘要】：土工袋是指装入土、砂等填料后形成的袋状物。其具有袋内填料不受限制、抗压强度高、减振、防冻融、抗碱性好等诸多优点,已被应用于地基加固、桩型复合地基、生态护坡、河海护堤、防冻胀和处理膨胀土、淤泥土等工程中。虽土工袋性能优越,而挡土墙又是岩土工程中很重要的一种结构形式,但因传统土工袋工法由多个袋体堆叠组合而成,袋体切断了内部填料间的联系,因此,土工袋在挡土墙中的应用需克服其整体性能差的缺点。针对土工袋挡土墙因上部土工袋摩擦滑移发生破坏的特征,本论文提出了连接式土工袋挡土墙的解决方案。连接式土工袋由带孔长方体土工袋和包塑不锈钢扎带组成,该方案可提高土工袋的承载能力和层间摩擦力。针对连接式土工袋的结构性能,论文做了以下几方面的研究:(1)基于土工袋挡土墙模型试验探讨了土工袋挡土墙的破坏模式,并从理论上分析了连接式土工袋挡土墙的工作机理。分析表明:连接式土工袋挡土墙的扎带受力后会产生一个拉力,该拉力可以起到增加挡土墙整体性的作用。(2)在土工模型槽中进行了连接式土工袋挡土墙模型试验,分别对挡土墙位移模式、墙后水平土压力、墙内水平土压力、墙后竖向土压力及扎带内力进行了研究。试验表明:连接式土工袋挡土墙较传统土工袋挡土墙承载力提高了约3倍,而破坏变形却减小了一半。(3)采用ABAQUS先模拟了土工袋单轴压缩试验,构建数值模拟时土工袋的本构模型,再分别模拟了土工袋挡土墙和连接式土工袋挡土墙以作对比。模拟结果验证了连接式土工袋挡土墙承载能力及变形性能均优于土工袋挡土墙的结论。(4)针对连接式土工袋结构在研究过程中发现的问题,对其施工工法做了改进。同时,结合工程实际应用,提出了包裹土工袋式加筋土挡土墙和贯穿土工袋式连续墙两种方案,并研究了两种方案的施工工法、适用情况及注意事项。论文创新点在于提出了一种连接式土工袋挡土墙方案,并从理论、模型试验、数值模拟三个方面进行了研究,最后探讨了该方案在工程应用中的适用性及可行性。这种方法解决了传统土工袋挡土墙整体性能差的缺点,并且适用范围广,从而为挡土墙的研究和应用提供了新的思路。
[Abstract]:Geotextiles are bags formed after filling with soil, sand and other fillers. It has many advantages, such as unlimited packing in bag, high compressive strength, vibration reduction, freezing and thawing resistance, good alkali resistance and so on. It has been used in foundation strengthening, pile type composite foundation, ecological slope protection, river and sea berm, frost heave prevention and treatment of expansive soil. In a project such as silt. Although the performance of geotextile bags is superior, and retaining wall is an important structural form in geotechnical engineering, because the traditional geotechnical bag method is composed of several bags, the bag body cuts off the connection between internal fillers. The application of geo-bag in retaining wall needs to overcome the shortcoming of its poor overall performance. In view of the characteristics of the earth bag retaining wall caused by friction and slip of the upper soil bag, this paper puts forward the solution of the connected earth bag retaining wall. The connected earth bag is composed of cuboid geotextile bag with holes and stainless steel strapping belt. This scheme can improve the bearing capacity and the friction between layers of the bag. According to the structural performance of the connected soil bag, the following aspects are studied in this paper: (1) based on the model test of the earth bag retaining wall, the failure mode of the soil bag retaining wall is discussed, and the working mechanism of the connected soil bag retaining wall is analyzed theoretically. The analysis shows that a tensile force will be produced after the tie band of the connected geotextile retaining wall is loaded, and this tension can increase the integrity of the retaining wall. (2) the model test of the connected geotextile retaining wall is carried out in the geotechnical model slot. The displacement model of retaining wall, the horizontal earth pressure behind the wall, the horizontal earth pressure inside the wall, the vertical earth pressure behind the wall and the internal force of the tie band are studied respectively. The test results show that the bearing capacity of the connected soil bag retaining wall is increased about 3 times than that of the traditional earth bag retaining wall, while the failure deformation is reduced by half. (3) Abaqus is used to simulate the uniaxial compression test of the soil bag. The constitutive model of geotextile bag is constructed, and then the geotextile retaining wall and the connected geotextile retaining wall are simulated and compared respectively. The simulation results verify the conclusion that the load carrying capacity and deformation performance of the connected geo-bag retaining wall are better than that of the geo-bag retaining wall. (4) the construction method of the connected geotextile bag structure is improved in view of the problems found in the research process. At the same time, combined with the practical application of the project, two schemes of encased geo-bag reinforced earth retaining wall and perforated geotechnical bag continuous wall are put forward, and the construction methods of the two schemes, their application and points for attention are studied. The innovation of this paper is to put forward a kind of connected geo-bag retaining wall scheme, and to study it from three aspects: theory, model test and numerical simulation. Finally, the applicability and feasibility of the scheme in engineering application are discussed. This method solves the shortcoming of the traditional geo-bag retaining wall with poor overall performance and has a wide range of application, thus providing a new way of thinking for the research and application of the retaining wall.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU476.4

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