双排抗滑桩土拱效应分析

发布时间：2018-07-20 20:28

【摘要】：抗滑桩被广泛使用在滑坡的治理中，大量工程实践证实其主要依靠土拱效应来阻挡桩间土体的滑出，进而起到抗滑的效果。土拱效应是土体产生不均匀变形，使得土体中主应力向桩体发生偏转的一种现象，桩后土拱效应长期以来为工程界所关注，特别是20世纪以来，关于土拱效应的实测数据、模型试验和理论研究逐渐增多。在滑坡治理中，对于存在一个明确滑动面且滑坡推力较大时，若设置一排抗滑桩则需很大的截面和桩长，导致成本偏高或支挡结构受力不合理，这时可以考虑采用双排或多排抗滑桩进行治理，而悬臂双排桩是双排抗滑桩中较为常见的一种，在切方滑坡和基坑支护中常常使用带挡板悬臂双排桩。目前对双排抗滑桩的研究还处于探索阶段，还没有成熟的理论和实用设计方法，对其工作机理也不甚清楚，，而对悬臂双排桩的研究就更加的少了，鉴于在实际工程中，带挡板悬臂双排桩被广泛的使用，因此本论文依托重庆市百名工程技术高端人才计划项目“悬臂式抗滑桩三维土拱效应及其动力灾变研究”（NO.0218002432010），通过室内模型试验和数值分析对带挡板悬臂双排桩的三维土拱效应进行研究分析，主要工作及结论如下：（1）在查阅相关文献的基础上，综述抗滑桩土拱效应及其形成机理的研究现状，总结分析了前人对土拱效应的研究成果。（2）设计悬臂桩室内模型试验，试验重点对桩身应变及其桩间土体的内部应力分布及桩周土拱效应的作用程度进行研究分析，分析了坡顶荷载和土体含水量对悬臂单排桩土拱效应的影响；分析了坡顶荷载、排净距和不同布桩方式对双排悬臂桩土拱效应以及前后排桩身内力的影响，在本文试验模型中，悬臂双排桩分为悬臂双排平行桩和悬臂双排梅花桩两种不同的布置方式。（3）利用大型通用有限元分析软件ABAQUS对悬臂双排桩进行了数值计算，并将数值计算结果与室内模型试验的分析结果进行对比研究，探讨前后桩桩排距、水平推力、挡板刚度对悬臂双排桩土拱效应和前后排桩身内力的影响，并对悬臂双排桩两种不同的布桩方式进行对比；并且与埋入双排桩和带连梁悬臂双排桩进行对比分析。
[Abstract]:The anti slide pile is widely used in the treatment of landslides. A large number of engineering practices have proved that it mainly relies on the soil arch effect to block the slippery soil between piles, and thus plays an anti slippery effect. The soil arch effect is a phenomenon of uneven deformation of the soil, which makes the main stress deflect to the pile body, and the soil arch effect after the pile has long been a project. Since twentieth Century, especially since twentieth Century, the model test and theoretical research on the measured data of the soil arch effect have increased gradually. In the treatment of landslides, if there is a clear sliding surface and the landslide thrust is large, if a row of anti slide piles is set up, a large section and pile length will be required, which leads to the high cost or the unreasonable force of the retaining structure. Double row or multi row anti slide pile can be considered, and cantilever double row pile is a common type of double row anti slide pile. Double row of cantilever pile with baffle is often used in the cutting side and foundation pit support. At present, the research on double row anti slide pile is still in the exploration stage, and there is no mature theory and practical design method. The mechanism is not very clear, but the research on the cantilever double row pile is less. In view of the practical engineering, the cantilever double row piles with baffles are widely used. Therefore, this paper relies on the "NO.0218002432010" of the "cantilever type anti slide pile three-dimensional soil arch effect and the dynamic catastrophe study" (NO.0218002432010). Through indoor model test and numerical analysis, the three-dimensional soil arching effect of cantilever double row piles with baffles is studied and analyzed. The main work and conclusions are as follows:
(1) on the basis of consulting relevant literature, the research status of soil arching effect and its forming mechanism of anti slide pile is summarized, and the predecessors' research results on soil arching effect are summarized and analyzed.
(2) an indoor model test of cantilever pile is designed. The experiment focuses on the analysis of the strain of pile body, the internal stress distribution of the soil and the effect degree of the soil arch effect on the pile, and analyzes the influence of the load of the slope top and the soil moisture on the soil arch effect of the cantilever single row pile, and analyzes the load of the slope top, the spacing distance and the different way of pile cloth. In this experimental model, the cantilever double row piles are divided into two different arrangement modes of cantilever double row parallel piles and cantilever double row of plum blossom piles in the experimental model.
(3) the cantilever double row pile is calculated by the large general finite element analysis software ABAQUS, and the numerical calculation results are compared with the analysis results of the indoor model test. The influence of the pile spacing, horizontal thrust and the stiffness of the baffle on the soil arch effect of the cantilever double row pile and the internal force of the front and rear piles is discussed, and the double row of cantilever row is also discussed. The pile is compared with two different pile arrangement methods, and is compared with the double row piles embedded with double row piles and cantilever beams with double beams.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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