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崩岗是华南花岗岩红壤区特殊的水土流失形式,而广东省的崩岗侵蚀隐患最为突出。选择广东省崩岗侵蚀典型区,通过野外采样和室内直接剪切试验,研究不同土壤水分含量对崩岗侵蚀区土体抗剪强度的影响(烘20 min、烘10 min、自然含水量、浸30 s和水分饱和)。结果表明:土壤水分对土体强度影响显著,当土壤含水率在15%时,对应的黏聚力c和内摩擦角φ指标均出现峰值;黏聚力c指标变化幅度较大,随着土壤水分含量的增加呈现先增大后减小的趋势,而内摩擦角φ一直处于衰减状态;抗剪强度指标随土壤水分含量变化呈非线性衰减,因此在评价崩岗稳定程度时,可依据土壤水分含量和抗剪强度指标作出预测。
Collapsing is a special form of soil and water loss in the southern part of the granite red soil region in South China, and the most serious potential for collapse in Guangdong Province is erosion. In this paper, the typical area of collapsing erosion in Guangdong Province was selected. Through field sampling and direct indoor shearing tests, the effects of different soil moisture contents on shear strength of soil in collapsing-erosion area were studied (bake 20 min, bake 10 min, natural water content, 30 s and water saturation). The results showed that soil moisture had a significant effect on soil strength. When the soil moisture content was 15%, the corresponding cohesion c and internal friction angle φ both showed peak values. The cohesion c index changed a lot. With the increase of soil The increase of moisture content firstly increases and then decreases, while the angle of internal friction φ is always in a decaying state. The shear strength index is nonlinearly decayed with the change of soil moisture content. Therefore, when evaluating the stability of collapse, Moisture content and shear strength index to make a prediction.