摘要
为分析降雨入渗条件下边坡暂态饱和区形成条件与演化特征,开展不同坡度条件下边坡降雨入渗数值模拟计算,分析降雨条件下边坡暂态饱和区形成条件,研究降雨强度、饱和渗透系数、坡度等多因素对边坡暂态饱和区演化特征的影响。研究结果表明,降雨条件下边坡暂态饱和区的形成条件为:①降雨强度大于等于岩土体饱和渗透系数;②降雨入渗进入饱和状态土控制入渗阶段。降雨条件下,降雨入渗影响区、暂态饱和区均持续向下扩展;降雨停止后,地下水位线以上的岩土体孔隙水压力、体积含水气量持续降低,且地下水位线不断升高。降雨强度小于岩土体饱和渗透系数时,降雨入渗影响区扩展速率与降雨强度呈正相关;降雨强度大于等于岩土体饱和渗透系数时,降雨入渗影响区、暂态饱和区扩展速率受降雨强度影响较小。降雨期间,降雨入渗影响区、暂态饱和区扩展速率与饱和渗透系数随深度的变化率δkz呈正相关,孔隙水压力峰值与δkz呈负相关;降雨停止后,地下水位线、孔隙水压力峰值与δkz呈正相关。降雨初期,降雨入渗影响区面积、孔隙水压力峰值与坡度呈正相关;降雨后期及降雨停止后,降雨入渗影响区面积、暂态饱和区面积、地下水位线高度与坡度呈负相关。
Numerical simulation of slope rainfall infiltration under different slope conditions were carried out to analyze the formation conditions and evolution characteristics of the transient saturation zone of slope under rainfall infiltration conditions.The influence of rainfall intensity,saturation permeability coefficient and slope on the evolution characteristics of the transient saturation zone of the slope was studied.The research results show that a transient saturation zone is formed inside the slope when the following two conditions are met,one is that the rainfall intensity is greater than or equal to the saturated permeability coefficient of the rock and soil body,and the other is that the rainfall infiltration enters the saturated state soil to control the infiltration stage.Under the condition of rainfall,the influence zone of rainfall infiltration and transient saturation zone expand downward continuously.After the rain stopped,the pore water pressure and volumetric water vapor content of the rock and soil above the groundwater level continued to decrease,and the groundwater level continued to rise.When the rainfall intensity is less than the saturated permeability coefficient of rock and soil,the expansion rate of the rainfall infiltration affected area is positively related to the rainfall intensity.When the rainfall intensity is greater than or equal to the saturated permeability coefficient of rock and soil,the expansion rate of rainfall infiltration affected area and transient saturated area is less affected by the rainfall intensity.During rainfall,the expansion rate of the rainfall infiltration affected area and the transient saturation zone is positively correlated with the change rate of the saturated permeability coefficient with depthδkz,and the peak pore water pressure is negatively correlated withδkz.After the rain stopped,the groundwater level and pore water pressure peak were positively correlated withδkz.At the initial period of rainfall,the area affected by rainfall infiltration and the peak value of pore water pressure are positively correlated with the slope.In the later stage of rainfall and after the rain stops,the area affected by rainfall infiltration,the area of transient saturation and the height of groundwater level are negatively correlated with the slope.
作者
邱祥
蒋煌斌
欧健
付宏渊
马吉倩
QIU Xiang;JIANG Huangbin;OU Jian;FU Hongyuan;MA Jiqian(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Key Laboratory of Road Structure and Materials Transportation Industry,Changsha University of Science&Technology,Changsha 410114,China;School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China;Team 402,Hunan Provincial Bureau of Geology and Mineral Exploration and Development,Changsha 410004,China)
出处
《水利学报》
EI
CSCD
北大核心
2020年第12期1525-1535,共11页
Journal of Hydraulic Engineering
基金
国家自然科学基金项目(51908073,51838001)
湖南创新型省份建设专项经费项目(2019SK2171)
湖南省教育厅科学研究项目(18C0188)
长沙理工大学土木工程优势特色重点学科创新性项目(18ZDXK15)。
关键词
边坡工程
降雨入渗影响区
暂态饱和区
孔隙水压力
体积含水气量
slope engineering
rainfall infiltration
transient saturation zone
pore water pressure
volumetric water vapor content
