华南活动型崩岗崩壁土体的崩解特性及其影响因素

发布时间：2018-03-07 00:27

本文选题：崩岗　切入点：崩壁　出处：《水土保持学报》2017年01期 　论文类型：期刊论文

【摘要】：崩岗的侵蚀过程主要是通过崩壁的坍塌作用来完成,崩壁土体的坍塌必然有水的参与,土体遇水将发生崩解现象,因此,研究崩壁土体坍塌需先研究其崩解特性。通过分层采集崩壁土体4个层次的土样,进行不同层次崩壁土体的理化性质和崩解特性测试分析。结果表明:(1)崩壁土体的4个层次(红土层、砂土层、碎屑层、碎石角砾残积层)的理化性质与风化壳的风化程度有密切联系,随风化程度的高低而有规律的变化。(2)在崩壁土体垂直剖面上,碎石角砾残积层的崩解速度最快,红土层最慢,崩解速度快慢表现为红土层砂土层碎屑层碎石角砾残积层;初始含水量对红土层、砂土层的崩解速度影响较大,对碎屑层、碎石角砾残积层的影响较少。(3)影响崩壁土体崩解特性的理化因子众多。其中对崩解速度有显著正相关影响的理化因子按相关系数大小排序为砂粒含量、MgO、自然含水量、K_2O、CaO、交换性钠、pH、Na_2O、孔隙度、阳离子交换量;有显著负相关影响的理化因子按相关系数大小排序为粘粒、Fe_2O_3、Al_2O_3、TiO_2、SiO_2、粉粒、有机质、游离氧化铁、游离氧化铝;只有交换性钙、饱和含水量、土粒比重、土粒干密度这4个因子与崩解速度的相关性不显著。崩壁不同层次土体的理化性质的分异性是崩解产生显著差异的基础,而崩壁土体崩解速度的层次分异性是崩壁坍塌的重要因素之一。
[Abstract]:The erosion process of rockfall is mainly accomplished by the collapse of the collapse of the wall. The collapse of the soil must involve the water, and the soil will collapse when it meets the water, so, It is necessary to study the collapse characteristics of collapsing soil. The soil samples of 4 layers of collapsing soil are collected by stratification. The physical and chemical properties and disintegration characteristics of different layers of avalanche soil were tested and analyzed. The results show that there are 4 layers (red soil layer, sand layer, clastic layer) of the collapse soil. The physical and chemical properties of the gravel residual layer are closely related to the weathering degree of the weathering crust. The rate of disintegration is shown as red soil layer, sand layer, debris layer, gravel residual layer, initial moisture content has great influence on the rate of decomposition of red soil layer, sand layer, and clastic layer, There are many physical and chemical factors that affect the disintegration characteristics of the collapse soil. Among them, the physical and chemical factors which have significant positive correlation to the disintegration rate are the sand content (MgO) and the natural water content according to the correlation coefficient. K2OCaO, pH of exchangeable Na\ +\ +\ {2}\ +\ {2}\ {2}\} _ 2, porosity, Cationic exchange capacity; physicochemical factors with significant negative correlation effects are in order of correlation coefficient: clay tipped, Fe2O3Al2O3, TiO2SiO2, silt, organic matter, free iron oxide, free alumina; only exchangeable calcium, saturated water content, soil specific gravity, There was no significant correlation between the dry density of soil particles and the disintegration rate, but the difference of physical and chemical properties of soil in different layers of collapse was the basis for the significant difference of disintegration. The hierarchical differentiation of collapse velocity is one of the important factors of collapse.
【作者单位】：佛山科学技术学院空间信息与资源环境系;
【基金】：国家自然科学基金项目“华南花岗岩红壤区崩壁裂隙发育对崩壁稳定性的影响”(41371041);国家自然科学基金项目(41401108)
【分类号】：S157.1

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