【作者】 常倩倩；

【导师】 束一鸣；

【作者基本信息】 河海大学 ， 水工结构工程， 2007， 硕士

【摘要】 土工格栅加筋挡土墙结构，由于具有良好的抗变形能力和抵抗震动的能力，被广泛应用于公路、铁路、建筑、水利等领域的工程实践中。然而该项技术在工程中的运用仍带有较大的经验性，理论研究远远落后于工程实践，尤其是在加筋间距对加筋挡墙破坏模式的影响及临界高度确定方面，相关的理论知识就更加少了。 为研究加筋间距在不同的地基和填土条件下对加筋挡土墙破坏模式及破坏机理的影响，本文采用基于三维拉格朗日显式有限差分方法的FLAC^3D程序对挡墙作稳定分析。通过模拟分析不同间距下多种工况的临界破坏状态，得出了一系列有益于工程设计和实践的结论。本文所做的主要工作如下： （1）简单介绍了加筋挡土墙的发展特点、应用情况和目前的理论研究，以及确定加筋土结构临界高度的几种理论方法。 （2）总结了土工格栅的工程特性、加筋机理及工程应用； （3）简要介绍了FLAC^3D有限差分程序的基本原理和特点，并以一座建造在成层地基单面板土工格栅加筋挡土墙实际工程为数值分析的研究对象，运用FLAC^3D程序进行了数值模拟计算，将计算结果与实测结果进行对比分析，验证了计算模型分析的合理性与有效性，据此为后面基于上述模型的加筋挡土墙的特性研究提供了实例验证； （4）通过模拟分析不同间距下多种工况的临界破坏状态，得出了主要的四种破坏模式。在对每种模式的破坏形成机理进行分析后，发现加筋间距是影响加筋挡土墙破坏模式的主要因素，很大程度上，间距的大小决定了模式的种类，随着间距的增大，破坏模式由外部破坏—复合破坏或深层滑动破坏—内部破坏发展；研究表明，地基和填土也影响着挡墙的破坏模式。地基较强时，破坏大多只在挡墙填土发生，反之，容易在挡墙填土和地基内产生贯通破坏；填土越强，挡墙越稳定，越不容易发生内部破坏。 （5）同时，对每种工况临界破坏状态的挡墙临界高度进行研究，为加筋挡土墙的设计和施工提供参考。本文所得结论对以后更多的相关主题研究具有参考意义。更多还原

【Abstract】 Geogrid-reinforced soil retaining walls, which are quite capable of resistance to deformation and motion, have been widely used in various fields, such as highway, railway, architectural engineering, hydraulic engineering and so on. But,in the real engineering application,this technique is based on some experients, the theoretical research is behindhand of engineering practice.However, the Theory on the analysis of retaining walls failure mode and the critical height determination is more less.In order to investigate the failure mode and failure mechanism of geogrid-reinforced soil retaining wall under different geogrid reinforcement space and different foundation as well as backfill soil, FLAC^3D based on three-dimensional Lanrangian explicit finite difference method is used for stability analysis of reinforced soil retaining walls. By simulating critical failure states of many cases with different reinforced spaces, the implications to design and construction based on the numerical results of current study are obtained The main work in this paper is followed as:（1） Introduce the development 、 application and current theory research on reinforced soil retaining wall, and Theoretical methods on critical height determination of reinforced soil retaining structures.（ 2 ） Generalize engineering characteristics 、 reinforcement mechanism and engineering application on geogrid;（3 ） Introduce the basic principle and features of a finite difference program FLAC3D.Compared the response calculated using FLAC^3D program to the observed behaviour, a case for an actual geogrid-reinforced soil retaining wall of one-side facing constructed on a layered soil foundation are investigated to verify the rationality and availability of the proposed numerical model, which is a good test for the following numerical studies on features of wall performance;（4） Four main kinds of modes have been verified. As the mechanisms of the failure modes are researched, reinforcement space is found to be a major influence factor of the failure mode, and it is result in different kinds of failure modes. As reinforcement space increases, the failure mode changes from external failure to compound failure or deep-seated failure and then to internal failure. Numerical simulations confirm that the failure zones develope only in the backfill soil when the retaining wall on the better foundation, while the更多还原