【作者】 苗英豪；

【导师】 胡长顺；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2003， 硕士

【摘要】 本文以陕西省省道305线土工格栅加筋路堤试验路为工程依托，通过有限元分析、离心模型试验以及试验路研究，对一般土质地基上土工格栅加筋粘性土路堤的机理进行了研究。采用有限元理论与方法对不同高度、不同边坡坡度、不同加筋密度、不同加筋长度的土工格栅加筋路堤及不加筋路堤进行了计算与分析，研究了各因素对格栅内拉力分布、路堤横截面上位移及应力分布的影响以及地基的响应情况。通过离心模型试验，对不同边坡坡度、不同加筋密度的土工格栅加筋路堤及不加筋路堤横截面上的位移分布进行了对比分析，对各模型在不利工作状况下地基的响应情况、路堤的整体变形情况、破坏情况及趋势进行了观察。通过试验路修筑对土工格栅加筋路堤的施工技术进行了研究，对路堤中土工格栅的应变进行了长期观测与分析。研究表明：土工格栅的加入使得路堤整体刚度得到提高，内部稳定性增强，对地基均匀性和抗变形能力的要求有所提高；土工格栅加筋路堤边坡坡度过缓不利于格栅作用的充分发挥，也不经济；适当增加路堤边坡坡脚以上部分的土工格栅密度有益于整体加筋效果；不等长加筋是较经济的选择；在填土虚铺厚度大于30cm的情况下，采用羊脚碾压路机碾压能有效减小土工格栅的损伤；实际工程中土工格栅的变形主要来源于施工的影响；雨水的入渗对土工格栅加筋路堤的稳定性极为不利。结合本文研究成果及我国现行规范中的不足，提出了设计建议：土工格栅在边坡处应进行反包施工，以提供足够的锚固力；应做好坡面防护和排水设计；必要时对地基承载力进行验算。更多还原

【Abstract】 This study focused on mechanism of geogrid reinforced clayey soil embankment on common earth foundation. It is conducted according to a test road located in TongChuan, North-West China’s ShaanXi province. Earth embankment and geogrid reinforced embankment with various slope, various spacing and length of the reinforcements, various heights were calculated by FEM. Each factor’s influence on the tensile stress of the geogrids, the stress and displacement distribution in the cross sections of embankments and the response of foundations were analyzed. A centrifuge testing program was undertaken to investigate the distributing of displacement on the embankments’ cross sections and to observe the performance of these embankments at failure or the failure trend of these embankments. The responses of foundations were also analyzed. Various slopes and various spacing of the reinforcements were considered in this testing program. And an earth embankment model as a comparison was tested. Construction technology of geogrid reinforced embankment and long term strain of geogrid in the embankment were also researched. The interpretation of FEM analysis and the experimental results provided insight into the performance of reinforced embankment. It is shown that the stiffness and the interior stability of the embankments are increased by reinforcements. The reinforced embankments need evener and stiffer foundations. Research also indicated the slope should be steeper than a critical inclination. Reducing the geogrid space around 1/4-1/3 height of the slope will enhance the stability of the embankment. And unequal length of reinforcements is economical. The bruises of geogrid are decreased if sheep-foot roller is used when lay-down thickness deeper than 30cm. The deformation of geogrid mainly conies of construction. The infiltration of rainwater is disadvantage for the stabilization of geogrid reinforced embankment. Some suggestions are made based on the results of this research and the shortcoming of "Technical Specification for Application of Geosynthetics in Highway", Geogrids should be overlapped on the slope. Much greater importance should be attached to slope protection and drainage system design. If necessary, checking computations of foundation bearing capacity should be done.更多还原