裂隙膨胀土渗流中裂隙模型建立方法

摘要

考虑裂隙对膨胀土渗透性的影响建立膨胀土裂隙模型,对于研究因降雨而形成的浅层滑坡灾害具有十分重要的意义.裂隙模型既要考虑符合现实情况也要考虑实施的可能性,为此提出一种结合现场裂隙图片、土体含水率和室内实验成果建立裂隙模型的方法.这种方法从达西定律出发建立了裂隙介质渗流的数学模型,基于裂隙膨胀土降雨实验对裂隙膨胀土降雨入渗过程进行简化,最后根据室内脱湿实验数据结果进行数值曲线拟合建立裂隙模型.将模型应用于Geostudio软件中,发现降雨入渗在裂隙膨胀土中的深度远大于无裂隙的情况,裂隙的存在对渗流场的影响主要表现为增大土体入渗边界,扩大降雨入渗的范围以及提高土体地表的入渗率.%To establish fissure expansive soil model with considering the impact of crack on expansive soil permeability has great significance for the study of shallow landslide disaster as rain.Fracture model is necessary to consider real situation and also should consider the possibility of the implementation, so a approach of binding site fissure pictures was proposed, soil moisture content and the results of laboratory experiments to establish fracture model.This method starting from Darcy`s law a mathematical model of the flow in fractured media was established and the rainfall infiltration process of fissure expansive soil based on rainfall experiments of fissure expansive soil was simplified.Finally, using the numerical curve fitting fissure model was established according to the experimental data results of dehumidifying indoor experiment.The model is applied in Geostudio software and finds that the depth of rainfall infiltration in fissure expansive soil is much greater than in the case of no cracks, and the main impact of the presence of fissure on the seepage is to increase soil infiltration border, expanding the scope of rainfall infiltration and increasing infiltration rate of soil surface.