【作者】 张克；

【导师】 杨庆；

【作者基本信息】 大连理工大学 ， 岩土工程， 2004， 硕士

【摘要】 土是散粒矿物、水、空气的聚合物，具有很低或者没有抗拉强度。加筋地基是在地基或路堤的适当位置加入具有抗拉能力的土工合成材料而组成的土工结构物。由于加筋的增强效应，将会大大提高地基或路堤的承载力，达到增强稳定性、减少不均匀沉降的目的。土工格栅作为一种新型的土工合成材料，由于具有高抗拉强度、低延伸率、高稳定性等特点而被选作加筋土主要加筋材料。 本论文正是在前人的研究基础之上，以大窑湾25万吨级专用矿石码头工程为背景，选用与实际工程相同的筋材和土料，进行能反映结构实际受力和变形特性的的室内加筋地基模型试验，着重研究了不同影响参数变化条件下加筋地基的性能，并对试验模型进行了数值分析，通过对试验结果的分析和整理得出了很多有益的结论，并提出了建议。论文具体完成的工作： (1) 比较全面的回顾了加筋土结构的发展历史，阐述了国内外在理论研究、模型试验、数值分析等领域的研究现状；介绍了塑料土工格栅及加筋土结构的特点。 (2) 设计了室内加筋地基的模型试验。在静力分步加载条件下研究了模型地基在加筋与不加筋情况下的性能；通过改变加筋层数Ⅳ、加筋长度b、加筋层顶面距基础底面距离u三个参数，研究了加筋地基性能变化的效果，提出了对于条形浅基础最佳加筋方案。 (3) 对试验结果进行了整理分析，详细评述了现存加筋理论的特点和适用范围，并详细探讨了土与格栅间的相互作用和理想筋材的受力机制，为加筋土更深入的理论研究提供了有益的参考。 (4) 在理论分析与模型试验基础上，利用大型有限元分析软件ANSYS对试验模型进行数值模拟，计算结果表明，静载条件下土工格栅加筋作用使地基土中竖向应力分布更加均匀，水平应力和剪应力均有不同程度的减小，并将计算结果与试验结果进行对比，两者基本吻合。更多还原

【Abstract】 The soil is mixture of disseminated values, water and gas. It has lowly resist-pull intensity. The reinforced foundation is a new kind of structure, which is added with geosynthetics as reinforcement material at the appropriate position in soil. If the reinforcement works effectively, it can greatly improve the bearing capacity and stability of the foundation. As one of the new geosynthetics, geogrids are chosen because of its high strength, low elongation and high stability.Based on the studies of predecessors, the paper is combined with Da Yao gulf 250 thousands tonnage special ore dock engineering. The model test, which can reflect the deformation characteristic of real structure under static step loads, is performed in a room, and the geogrid and filling soil are same to field condition. The capability of the reinforced foundation with different parameters also be researched. Further more, its nonlinear behavior under excitation was analyzed by Finite Element Analysis program. Finally, some beneficial conclusions are found and some suggestions are put forward. The main work are as follows:(1) Look back generally to elaborate the history and development of the reinforced soil structure, and the research situation in the fields of theoretic, model tests, and numerical analysis at present. And the characters of geogrid and the reinforced soil also be introduced.(2) Design an indoor reinforcement foundation model test. Compare the reinforced foundation characteristic with the unreinfoced one under static loads. Change three parameters, which are the number of geogrid layers N , the length of the geogrid layer b, and the distance between the bottom of the foundation and the top geogrid layer u, to research the influence of them under the condition of loads. And advise an optimal reinforcement project for strip shallow foundation.(3) Analyze the results of the model test, and comment the merit and defect of the current reinforcement theory and their applicability in detail. Furthermore, the action between geogrid and filling soil and the perfect action mechanism also be discussed. It would be beneficial to the furthermore study.(4) Basted on the studies of theoretics and model test, the model was simulated by FEM software ANSYS. The calculate results indicate that reinforcement by geogrid make the vertical stress distribution more average and the horizontal stress, shear stress decrease. Finally, compare with the model test results, the simulated analysis results are in good agreement with them.更多还原