【作者】 刘辉；

【导师】 秦志斌； 肖泽林；

【作者基本信息】 长沙理工大学 ， 工程硕士（专业学位）， 2015， 硕士

【摘要】 国内外对于高液限土的研究一般围绕着两个方面进行,一方面是高液限土本身的物理、力学特性和工程性质的认识;另一方面是高液限土的合理处治利用问题。高液限粘土天然含水率大,液限高,塑性指数大,水稳定性差,由于物理性能和工程特性,将其直接用于路基填筑,将产生压实度不足、翻浆、边坡坍塌等一系列病害。因此,系统地开展改良高液限粘土路用性能研究,具有重要的工程实际意义。本文依托常德市桃花源机场快速路建设工程,对高液限粘土的物理、化学性质进行了比较深入的分析,分别进行了基本物理性质试验、物质组成测试、干法、湿法击实试验、CBR试验、室内承载板试验,试验结果表明,机场快速路路基填筑所用的高液限粘土不符合路床填筑要求。针对高液限粘土提出了不同的改良试验方案,分别掺入不同比例的砂砾、水泥和石灰进行改良,经过改良后的高液限粘土在CBR值和回弹模量上均得到了相应提高,改良后高液限粘土的路用性能指标均达到了常德市机场快速路路基填筑的要求。通过试验路的铺筑,进一步验证了室内改良试验的研究成果,同时提出了改良高液限粘土填筑路基的施工工艺和质量控制要求,为同类工程建设提供参考。结合常德市建材价格对不同的高液限粘土改良方案的经济效益进行分析,表明掺20%砂砾的费用低于掺3%水泥或者3%石灰的费用,掺30%砂砾的费用最高。更多还原

【Abstract】 At home and abroad is generally around two aspects for research high liquid limit soil, on the one hand it is to recognize that the physical and mechanical properties and engineering properties of high liquid limit soil; On the other hand it is reasonable treatment utilization of high liquid limit soil. Features of high liquid limit soil are: large natural water content, high liquid limit, big plastic index and poor water stability. In view of the physical mechanics and engineering properties, it may lead to a series of diseases, such as inadequate compactness, frost boiling, sideslip and collapsing etc, if it was directly used for subgrade filling, Therefore, systematically carrying out the study on improving pavement performance of high liquid limit clay has great engineering meaning.The paper deeply analyses the physical and chemical property of high liquid limit clay by relying on airport expressway construction of Changde paradise. It respectively conducted basic physical property test, material composition test, dry and wet compaction test, CBR test and indoor plate-bearing test. Tests show that the high liquid clay used in airport expressway’s subgrade filling does not meet the requirements of the roadbed filling. It puts forward different improvement testing programs on high liquid clay, respectively incorporated in different proportions of gravel, cement and lime make improvements and all the modified high liquid clay CBR value and rebound modulus were improved accordingly, besides, pavement performance indicators of the modified high liquid limit clay reached the requirements of Changde Municipal road embankment filling.Paving of test road further verified research achievements of indoor improved tests and proposed the construction process and quality control requirements of improved high liquid limit clay subgrade filling, which provided references for construction projects of the same kind. Combined with the building materials prices of Changde, it analyzed the economic benefits of different high liquid clay improvement programs. And it shows that the cost of high liquid limit soil that is mixed with 20% gravel is less than that of mixed with 3% cement or 3% lime, andthe expense is highest for which is mixed with 30% gravel.更多还原