【作者】 马吉倩；

【导师】 彭波；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2009， 硕士

【摘要】 针对天津滨海地区具有四季温度变化大、地下水位埋藏浅、土的粘粒含量高、毛细水上升高度大、降水量大且集中等自然条件,使得滨海盐渍土形成春季积盐、表层含盐量大、毛细作用强烈的特点,结合当地材料供应现状,研究无机结合料加固氯盐渍土用于路基填料。课题首先测试分析了滨海氯盐渍土的土工性质,针对滨海新区土性,利用石灰、粉煤灰等无机结合料单一或组合加固滨海氯盐渍土,在试验研究各种加固土压实的基础上,对加固滨海氯盐渍土的力学性能和路用性能进行系统研究,包括不同龄期无侧限抗压强度、加州承载比、界限含盐量、抗冻性能、温缩性能、水稳定性、抗压模量等。在抗冻性能研究中,提出冻融稳定次数和抗冻稳定系数评价指标。采用灰色关联理论和偏离度指标,对不同配合比的加固效果进行综合性能评价,针对滨海地区的特点,提出了盐渍土填筑于路堤的不同含盐量范围下的适宜配合比。利用X-Ray衍射确定不同龄期加固土的生成物,同时采用扫描电镜观察生成物的形貌,通过形貌推测生成物的类型,验证X-Ray衍射试验结论。系统研究无机结合料加固氯盐渍土的微观加固机理。针对盐渍土路基盐胀、溶陷等主要破坏形式,采取结合料加固技术和隔离层技术进行综合处治措施,确保路基耐久性和良好的路用性能。更多还原

【Abstract】 In condition of great temperature difference, upper underwater table, much clay, more height of capillary rise, higher precipitation intensity, etc., saline soil in Binhai new area show features as follows: salt accumulation in the top in spring, salt crystallizing with the density of salt resolution, serious capillary action. Considering of the local material’s current situation, inorganic binding materials was used to consolidate chlorine saline soils as Subgrade padding. This topic first test and analyze the chlorine saline soil’s geotechnical properties in the Binhai area, and then on the basis of the obtained geotechnical properties, lime and fly ash was used to consolidate chlorine saline soil in Binhai area singly or mixed. After the compaction experiments on many kinds of consolidated soil, a systematic study on the mechanical properties and road-relate performance of consolidated chlorine saline soil was carried out, including the research on unconfined compression strength of different ages, California bearing ratio(CBR), limit salinity, anti-frozen performance and thermal shrinkage performance, water stabilizer performance, compressive resilience modulus, etc. In the research of the properties of frost resistance, a evaluation index of freeze-thaw stability times and anti-frozen stability coefficient have been proposed. Consolidation effect of different mix ratios have been comprehensive evaluated via the grey correlation theory and degree of deviation. On basis of the soil features of Binhai new area, proper mix ratios under different salinity saline soil which will be used for filling the embankment was proposed. The structure and morphology of the products from consolidation soil with different ages are characterized by X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The morphology of the products infered the type of the products and test the results of XRD. The consolidation mechanism of inorganic binding materials to consolidate chlorine saline soil was systematicly studied. Binding material’s strengthening technique and isolation layer technique was used to treat with salt dilate and collapsibility which are caused by saline soil in order to ensure the Subgrade durability and well road performance.更多还原