【摘要】 针对非饱和膨胀土边坡问题,考虑降雨、地表水入渗、地下水径流、地表蒸发、植被蒸腾等因素的作用,运用二维非饱和渗流模型求解不同气候条件下膨胀土边坡孔压、体积含水量的变化情况,通过分析得到如下结论:①持续降雨后,坡体内吸力减小,其中坡脚处的孔压最先达到正值,其次是坡中,最后是坡顶,因此持续降雨可扩大饱和区的范围,使边坡安全度降低;②坡脚、坡中及坡顶处体积含水量的差异除与土体孔压相关外,还与土体的水分特征曲线参数相关;③降雨-蒸发的干湿循环促使膨胀土滑坡内部土体的孔压、含水量的变化,从而形成裂隙,减小强度,降低边坡的安全度.更多还原

【Abstract】 The vadose fields and failure problems of unsaturated expansive soil slope are discussed in this paper by numerical analysis with improved two-dimensional Richards seepage model to analyze the variations of pore pressure and water content in the slope under different climate conditions,considering the action of rainfall precipitation and runoff as well as the evaporation by ground and vegetation.The results of the calculation and analysis can be described as follows: The suction in the slope decreases after persistent rain,and the toe of slope will be saturated firstly,then the middle of slope and top of slope lastly.Therefore,the area of saturation will be enlarged by continuous rainfall.The difference of water content in different part of the slope is also related to the parameter of soil-water characteristic curve besides to the pore pressure in the slope.Wetting-drying cycle of precipitation and evaporation is the important factor of landslides of expansive soils for variation of water content,hence fissure appears and decreases the strength.更多还原