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山区流域植被发育斜坡的失稳往往尾随着强降雨而发生,降雨入渗引起的地下水位上升是导致斜坡失稳的主要原因,而饱和渗透系数是评价土体渗透特性的主要参数。以植被发育斜坡土体为研究对象,应用CT扫描技术获得了土体孔隙尺寸分布,发现孔隙成圆率随着等效直径的增大有减小的趋势,即孔隙截面积越大,其形状越复杂。根据毛细管束模型预测出饱和渗透系数,再与环刀法测得的饱和渗透系数对比,发现预测值和实测值在相同数量级范围内,但还是存在一定的偏差。进一步对模型优化,修正孔隙形状系数后,模型的预测精度得到了显著提高。
The slope instability of vegetation development in mountainous area often occurs with heavy rainfall. The rising of groundwater level caused by rainfall infiltration is the main reason of slope instability. Saturated permeability coefficient is the main parameter to evaluate soil permeability. Taking the vegetated slope soil as the research object, the pore size distribution of the soil was obtained by CT scanning technology. It was found that the circularity rate of the soil decreased with the increase of the equivalent diameter. That is, the larger the cross-sectional area of the pore, The more complicated. According to the capillary beam model, the saturation permeability coefficient is predicted. Compared with the saturated permeability coefficient measured by the ring knife method, the predicted value and the measured value are within the same order of magnitude, but there is still some deviation. After further optimizing the model and correcting the pore shape coefficient, the prediction accuracy of the model has been significantly improved.