泥岩路堤降雨入渗数值分析及处治措施研究

发布时间：2018-07-03 10:20

本文选题：泥岩 + 路堤　；参考：《合肥工业大学》2017年硕士论文

【摘要】：泥岩是一种介于硬岩与土体之间的材料,在我国范围内广泛分布,它具有抗压强度低、易风化、遇水易软化、崩解,填筑密实度对含水率敏感等特点,对道路修建极其不利。因此,本文针对泥岩特性、泥岩路堤降雨入渗及相应处治措施进行研究。本文通过理论分析和试验研究,开展了如下工作:(1)对泥岩试样进行室内试验研究,由试验结果知,泥岩满足路堤填料的承载比要求,可以作为路堤填料,但泥岩属于软化岩石,遇水后强度降低,因此选取泥岩作为路堤填料需要特别注意泥岩的防水。(2)对泥岩进行改良试验研究,利用水泥或者石灰进行泥岩的改良能增强泥岩的水稳定性及承载比,石灰不仅价格便宜,而且石灰改良土存在最佳石灰掺入比,推荐选用石灰进行泥岩的改良。(3)采用路堤一维土体渗流模型结合持续降雨入渗模型(FDEM)的边界条件,基于全隐式有限差分法,计算出泥岩路堤土体的含水率。试验段检测值与理论值具有较高的相似性,证明了此种路堤含水率计算方法,具有良好的适用性和科学性。由计算结果可知,粘土封层的铺设能降低路堤表层土体降雨入渗速率,减小降雨对路堤含水率的影响深度。提出了两种计算粘土封层阻渗量的方法,阻渗量计算结果表明,粘土封层的铺设能够将大量的雨水阻隔在泥岩路堤之外,保护泥岩路堤。(4)在泥岩路堤修筑现场进行粘土封层的铺筑试验,定量研究在同次降雨条件下,粘土封层厚度、路堤深度、泥岩风化程度、晾晒天数等因素对路堤含水率的影响。针对安徽省泥岩路堤修筑提出合理的粘土封层铺设厚度。通过统计非线性回归分析,提出多因素与路堤含水率之间的预估模型。据此模型可计算出最佳填筑含水率状态下泥岩所处的路堤深度,降雨过后据此进行翻晒,节约施工时间及工程量。(5)选取试验段进行泥岩路堤冲击碾压试验研究,结果表明,冲击碾压遍数以20遍为宜,路堤每铺筑120cm进行一次冲击碾压,能够起到良好的效果。
[Abstract]:Mudstone is a kind of material between hard rock and soil, which is widely distributed in our country. It has the characteristics of low compressive strength, easy weathering, easy softening when encountered with water, collapse and sensitivity of filling density to water content, which is extremely disadvantageous to road construction. Therefore, the characteristics of mudstone, rainfall infiltration of mudstone embankment and corresponding treatment measures are studied in this paper. Through theoretical analysis and experimental study, the following work has been carried out in this paper: (1) the laboratory test of mudstone samples shows that mudstone meets the loading ratio requirement of embankment filler and can be used as embankment filler, but mudstone belongs to softening rock. The strength of mudstone decreases after water treatment, so it is necessary to pay special attention to the waterproofing of mudstone when selecting mudstone as embankment filler. (2) improving mudstone by using cement or lime to improve mudstone can enhance the water stability and bearing ratio of mudstone. Lime is not only cheap in price, but also has the best lime mixing ratio. Lime is recommended for mudstone improvement. (3) one dimensional seepage model of embankment and boundary condition of continuous rainfall infiltration model (FDEM) are adopted. Based on the fully implicit finite difference method, the moisture content of mudstone embankment is calculated. There is a high similarity between the measured values and the theoretical values of the test section, which proves that the method of calculating the moisture content of the embankment has good applicability and scientific character. From the results of calculation, it can be seen that the laying of clay seal layer can reduce the infiltration rate of the surface soil of the embankment and the depth of the influence of the rainfall on the moisture content of the embankment. Two methods for calculating the impermeability of clay sealing layer are presented. The calculation results show that the laying of clay seal layer can block a large amount of Rain Water outside the mudstone embankment. Protection of mudstone embankment. (4) Clay sealing test was carried out in the site of mudstone embankment construction. The effects of clay sealing layer thickness, embankment depth, mudstone weathering degree and drying days on embankment moisture content were quantitatively studied under the same rainfall condition. According to the construction of mudstone embankment in Anhui Province, a reasonable thickness of clay seal layer is put forward. Through statistical nonlinear regression analysis, the prediction model between multi-factors and embankment moisture content is proposed. According to the model, the depth of mudstone embankment under the condition of optimum water content can be calculated, and the depth of mudstone embankment can be calculated after rainfall, and the construction time and engineering quantity can be saved. (5) the impact rolling test of mudstone embankment is carried out by selecting the test section, and the results show that, The best impact compaction number is 20 times, and the impact compaction for every 120cm paving embankment can have a good effect.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.1

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