鄂尔多斯砒砂岩冻融特性试验研究

发布时间：2018-05-16 05:15

  本文选题：冻胀率 + 含水率　； 参考：《内蒙古农业大学》2015年硕士论文

【摘要】：由于内蒙古砒砂岩区属典型的温带大陆性气候,四季分明。在冬春两季,日间因太阳辐射的照耀而使温度急剧上升,因此形成“融解”现象,而夜间由于温度急速下降从而产生“冻结”现象,在昼夜之间交替出现“融解”和“冻结”现象,砒砂岩土壤随之热缩冷胀,“水”、“冰”相变频繁,使得土壤结构更加松散,胶结力变差,加剧砒砂岩的风化过程,地表土层因冻融而发生结构上的变异,相应地砒砂岩发生了冻融侵蚀。砒砂岩区强烈的侵蚀、流失和边坡稳定问题与砒砂岩的季节冻胀有着密切的关系,其冻胀作用改变了砒砂岩的内部结构,直接影响其物理力学性能。为了研究含水率、冷端温度、干密度与砒砂岩冻胀率的关系,文中针对内蒙古鄂尔多斯市准格尔旗砒砂岩进行不同含水率、不同温度、不同干密度下多因素耦合冻胀试验。研究结果表明：砒砂岩含水率在11%以下时,几乎不发生冻胀；含水率为12%-16%时,冻胀率与含水率之间存在着良好的线性关系,随含水率增加呈线性增大。确定了砒砂岩在-10℃的起始冻胀含水率,不在砂岩的冻胀率范围之内,所以砒砂岩的岩性有待进一步的确定；冻胀率随干密度的增大而增大,当冷端温度达到-20℃时,表现异常；冻胀率随冷端温度的降低而增大,但干密度为1.85g/cm3的试件,冻胀率随冷端温度的降低冻胀率有减小态势。含水率、冷端温度对砒砂岩冻胀率影响显著,干密度次之。运用spss软件对试验数据进行多元非线性回归,确定了含水率、干密度、冷端温度多因素耦合作用下冻胀率的回归方程。
[Abstract]:Due to the typical temperate continental climate in the soft sandstone area of Inner Mongolia, the four seasons are distinct. During the winter and spring seasons, the temperature rises sharply during the day due to the sun's radiation, thus forming a "melting" phenomenon, while the "freezing" phenomenon occurs during the night due to the rapid drop in temperature. The phenomena of "melting" and "freezing" appear alternately between day and night, and the soil in the soft rock becomes hot, shrinking and expanding, and the "water" and "ice" phase change frequently, which makes the soil structure more loose and the cementation force worse, thus exacerbating the weathering process of the arsenopyst. Due to the structural variation of the surface soil layer due to freezing and thawing, thawing erosion occurred correspondingly in the arsenopyst. The strong erosion loss and slope stability are closely related to the seasonal frost heaving of the soft rock. The frost heaving changes the internal structure of the soft rock and directly affects its physical and mechanical properties. In order to study the relationship between water content, cold end temperature, dry density and frost-heaving rate of arsenitic sandstone, the coupling frost-heaving test was carried out under different moisture content, different temperature and different dry density for arsenopyst rock in Zhungeer Banner, Ordos City, Inner Mongolia. The results show that there is almost no frost heave when the water content is below 11%, and there is a good linear relationship between frost heave and water content when the water content is between 12% and 16%, and increases linearly with the increase of water content. The initial frost-heaving water content of Pisha sandstone at -10 鈩，

本文编号：1895600