【作者】 支喜兰；

【导师】 王秉纲；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2006， 博士

【摘要】 由于黄土地区地形较复杂，山区的高等级公路出现了较多的高路堤和深路堑，数十米高的路堤已经屡见不鲜。显然，高路堤的地基必需满足一定的强度和变形要求，才能保证路基路面的整体稳定性。但是，迄今为止，我国公路领域尚没有路基地基承载力标准。随着黄土地区公路建设经验的不断积累，人们越来越意识到路基地基的重要性。为了避免由于地基承载力不足导致路基路面发生破坏，有必要研究公路路基地基承载力评价问题。 本文借鉴相关领域和行业的研究成果，对黄土地区公路路基地基承载力评价方法进行了系统的研究。对黄土地区高等级公路路基地基设计和施工技术现状、路基路面病害进行了调查分析，认为应该加强高等级公路尤其是较高路堤地基的勘察手段和力度。对黄土地区四个试验场地开展了地基承载力测试方法现场试验研究，分析了各种地基承载力测试方法在公路路基工程中的适用性，黄土地区公路路堤地基承载力评价时，不宜大规模采用载荷试验，可采用旁压试验。根据大量实测资料，对黄土地基承载力影响因素进行了分析，黄土地基承载力具有明显的区域性变化规律，含水量是影响黄土地基承载力的最敏感因素，液限和孔隙比是对黄土地基承载力影响较大的因素，黄土地基承载力和压缩模量之间具有良好的相关关系。在此基础上，开展了黄土地基承载力区划研究，将黄土地基承载力分为四个区域，以含水量、液限、孔隙比作为变量，建立了黄土各区域地基承载力非线性回归关系式和承载力表，精度较相关成果提高。运用模糊数学原理，建立了黄土地基承载力模糊评判模型，选择与黄土地基承载力密切相关的含水量、天然密度、孔隙比、液限为基本因素，同时考虑压缩系数和地形地貌的影响，编制了黄土地基承载力模糊评价程序，其预测精度较高。应用有限元方法，对黄土地基公路路基结构进行了变形分析，地基土变形模量、填土高度、路基宽度是影响路表沉降量和不均匀沉降率的主要因素，路表沉降量绝大部分是因地基沉降而引起的，提出了路表容许沉降变形建议值和黄土地基容许沉降变形。经对建筑地基承载力的相对容许变形修正、基底宽度修正和柔性修正后，提出了公路路堤黄土地基承载力设计值和黄土地区公路路堤地基承载力验算方法。通过调查，对公路路基黄土地基处理方法和效果进行了探讨，提出了公路路基黄土地基处理建议。更多还原

【Abstract】 Owing to the complicated topography in loess area, there are more and more high fills and deep cuts in high-grade highways of mountain area, and some embankments up to dozens of meter are nothing new now. It s obviously that the ground of high embankment should satisfy certain requirements of strength and deformation in order to guarantee the whole stability of embankments and pavements. But up to now, there is no criterion of ground bearing capacity for highway embankments in China. As highway construction experience accumulated in loess area, more and more people realize the importance of ground bearing capacity. In order to avoid the destructions of embankments and pavements due to insufficiency of the ground bearing capacity, it is necessary to study the evaluation of ground bearing capacity for highway embankments.Based on some results of related fields and industries, this paper researches systematically on the evaluation method of ground bearing capacity for highway embankments in loess area. Investigation on present situation of embankment ground design and defects of high-grade highway in loess area demonstrated the necessity to strengthen the reconnaissance of high-grade highway, especially the high embankment. The ground bearing capacity in four testing fields of loess area was conducted, and the adaptability of each testing methods was also analyzed. When the ground bearing capacity is evaluated for highway embankments in loess area, the large-scale bearing tests are not suitable and the compressuremeter tests are better. According to a great quantity of test data, the influence factors of ground bearing capacity in loess area were discussed. The loess ground bearing capacities are not same in the different regions. The water content of loess is the most sensitive factor to affect the ground bearing capacity. The liquid limit and the void ratio of loess are more sensitive factor to affect the ground bearing capacity. The correlation between the ground bearing capacity and the compression modulus of loess is good. Based on the above results, the ground bearing capacity districts of loess area were divided into four regions. The non-linearity regression formulas in the four regions and the tables of ground bearing capacity were established with the water content, the liquid limit更多还原