干密度和含水率对岩溶地区黄壤抗剪强度的影响——以重庆市南川区木渡河小流域为例

选择广泛分布于岩溶地区的黄壤,通过对室内三轴剪切试验,测定含水率和干密度交互作用对土壤抗剪强度指标的影响。试验表明:(1)在相同干密度情况下,黄壤粘聚力c随着含水率的增加呈现出先增加后减小的趋势,在相同土壤含水率水平下,粘聚力c随干密度增大而增大;黄壤内摩擦角φ在各干密度条件下均随着含水率增加呈明显减小的趋势,衰减速率基本一致;同一含水率水平下,内摩擦角φ随干密度变化不明显,土壤干密度为1.6g/cm3内摩擦角相对较大。(2)含水率和干密度的交互作用对黄壤粘聚力c有显著影响,粘聚力c在1.3~1.7g/cm3范围内随着干密度的增大而增大,且每一个干密度都有一个特定含水率与之对应,在这样一个交互作用下粘聚力c达到最大。(3)含水率和干密度的交互作用对内摩擦角φ影响相对较小,同一干密度下,其φ值差异不大,随干密度的增大缓慢增大,相对而言,含水率对内摩擦角φ的影响更明显,黄壤内摩擦角φ随含水率的增大呈非线性下降。 

The effect of dry density and soil water content on yellow soils hearing strength in karst area

Based on the triaxial shearing test in laboratory, the effect of soil water content and dry density on yellow soil shearing strength was determined. Experimental data indicated that: (1)the soil cohesive force firstly increase and then decrease with the increase of soil water content under the same soil dry density, and it increase with the increase of soil dry density under the same soil water content. The internal frictional angle of yellow soil fleetly decrease with the increase of soil water content under the same soil dry density, and it do not change obviously with the increase of dry density under the same soil water content. (2) The interaction of soil water content and dry density has significant impact on soil cohesive force, and the soil cohesive force reached to the maximum under the interaction of soil water content and dry density that each soil dry density matched the specifically soil water content. (3) The interaction of soil water content and dry density is small relatively on the internal frictional angle, and the internal frictional angle tardily increase with the increasing of soil dry density. Soil water content have relatively more obvious impact on the internal frictional angle, and the internal frictional angle of yellow soil nonlinearly decrease with the increasing of soil water content.