黄土填料CBR值的影响因素及其规律研究

发布时间：2018-03-16 16:08

本文选题：黄土　切入点：CBR　出处：《长安大学》2014年硕士论文　论文类型：学位论文

【摘要】：黄土地区通常将黄土作为路基填料填筑路基，黄土路基的稳定性很大程度上决定了道路的工作性能和运营状况。CBR作为柔性路面设计的重要参数和作为路基填料强度的指标对于道路的影响显得尤为重要，，目前对于CBR值的选取通常都采用统一的标准，这明显与实际情况有区别，如能结合各地区的气候条件合理的的选取CBR值对道路的设计和修筑具有重大的意义。为了研究CBR值在不同影响因素作用下的变化规律，本文以甘肃孔家塬和陕西石家庄黄土剖面所取的黄土为研究对象，通过CBR室内试验对两个剖面的黄土样CBR值的影响因素作了研究。利用二次正交回归试验设计方法对石家庄剖面黄土样进行研究，设计了CBR值在不同压实度、不同含水量以及不同浸水时间作用下三因素四水平的正交试验，根据实验结果得出了CBR值在三个因素作用下的二次正交回归公式，通过对回归公式的分析，得出了黄土CBR值在单因素和多因素作用下的变化规律。对两个剖面的黄土样进行了一定次数（分别进行1、3、5、7、10次）的冻融循环作用,试验试件在最佳含水量条件下进行标准重型击实，通过试验研究得出了试件表面状况变化情况、冻融作用后试件浸水前后CBR值的变化规律以及试件冻融过后内部含水量的变化规律。通过试验结果分析得出了CBR在各个因素作用下的变化规律，对于黄土分布区路基的设计和施工具有一定的指导意义。
[Abstract]:Loess is usually used as subgrade filler to fill the roadbed in loess area. To a great extent, the stability of loess subgrade determines the working performance and operation condition of road. CBR, as an important parameter in the design of flexible pavement and as an index of the strength of subgrade filler, is especially important for the influence of road. At present, a unified standard is usually adopted for the selection of CBR value, which is obviously different from the actual situation. For example, it is of great significance to design and build roads by selecting the CBR value combining with the climatic conditions of various regions. In order to study the variation of CBR value under the influence of different factors, the loess in the loess section of Kongjia Plateau and Shijiazhuang, Shaanxi Province is taken as the research object in this paper. The influencing factors of CBR value of loess samples from two sections were studied by CBR laboratory test. The loess samples of Shijiazhuang section were studied by quadratic orthogonal regression test, and the CBR values were designed in different compaction degrees. According to the results of orthogonal experiments with three factors and four levels under different water content and different soaking time, the quadratic orthogonal regression formula of CBR value under the action of three factors is obtained, and the regression formula is analyzed. The variation law of loess CBR value under the action of single factor and multiple factors is obtained. The freezing and thawing cycles of loess samples in two sections are given for a certain number of times (1 / 3 / 5 / 7 / 7 / 10 respectively). The standard heavy compaction was carried out under the optimum water content, and the change of the surface condition of the specimen was obtained through the experimental study. After freezing and thawing, the variation law of CBR value and internal water content after freezing and thawing were obtained. Through the analysis of test results, the variation law of CBR under the action of various factors was obtained. It has certain guiding significance for the design and construction of subgrade in loess distribution area.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1;U414

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