西峰黄土剖面地层CBR值分布规律研究

发布时间：2018-04-02 04:17

本文选题：黄土地层　切入点：黄土路基　出处：《长安大学》2014年硕士论文

【摘要】：路基是路面的基础，它承载着自身重力以及上部荷载，其强度及稳定性与整个道路的使用寿命相关。在中国西北地区黄土分布广泛，黄土被归类于特殊土，其工程性质也比较特殊。黄土孔隙发育，湿陷性强，遇水易产生不均匀沉降，部分黄土具有湿陷性，这些性质对公路路基影响很大。作为路基选择填料的依据，CBR不可避免的要与黄土联系在一起。虽然黄土路基的CBR值在规范中有规定，但由于黄土地层复杂，每个黄土层的CBR值又不尽相同，因此对各个地层黄土CBR值的研究十分有必要。首先，本文将以黄土的CBR试验为核心，所用材料选用甘肃西峰孔家塬黄土剖面进行研究。先将孔家塬剖面地层细分为67小层，对每一小层黄土分别做CBR试验，然后将试验结果汇总，，分析CBR值分布，并得出规律。其次，根据土的三相比例指标的定义，换算出甘肃孔家塬剖面各个黄土地层的三相比例指标，并得出各指标与地层深度的关系。最后，将孔家塬黄土地层剖面的CBR值与洛川黄土地层剖面的CBR值相比较，找出规律。分析了形成这一规律的原因，研究成果对黄土地区的高等级公路建设具有指导作用。
[Abstract]:Subgrade is the foundation of pavement, it bears its own gravity and upper load, and its strength and stability are related to the service life of the whole road.Loess is widely distributed in northwest China, loess is classified as special soil, and its engineering properties are also special.The porosity of loess is developed, the collapsibility is strong, the uneven settlement is easy to occur when the water is encountered, and some loess have collapsibility, these properties have a great influence on the roadbed of highway.As the basis of selecting filling for subgrade, CBR is inevitably associated with loess.Although the CBR value of loess roadbed is stipulated in the code, because of the complexity of loess layer and the different CBR value of each loess layer, it is necessary to study the CBR value of loess in each stratum.Firstly, the CBR test of loess is taken as the core, and the loess section of Xifeng Kongjia tableland in Gansu Province is selected for study.The strata of Kongjiayuan section are subdivided into 67 layers, and each layer loess is tested by CBR test, then the test results are summarized, the distribution of CBR value is analyzed, and the rule is obtained.Secondly, according to the definition of soil three-phase ratio index, the three-phase ratio index of each loess layer in Kongjiayuan section of Gansu Province is converted, and the relationship between each index and formation depth is obtained.Finally, the CBR value of the loess layer section in Kongjia Plateau is compared with the CBR value of the loess layer section in Luochuan, and the regularity is found out.This paper analyzes the reasons for the formation of this law, and the research results can guide the construction of high-grade highway in loess 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

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