降雨入渗条件下路基含水率空间分布

Spatial Distribution of Subgrade Moisture Content under Rainfall Infiltration Conditions

为探究降雨入渗条件下路基土体含水率空间分布规律,在路基不同深度截面埋设TDR水分传感器,连续观测路基含水率变化,并通过有限元分析软件进行数值仿真分析,对比研究实测值与仿真值的差异。研究表明,降雨入渗对路基含水率的影响存在滞后性,路基顶面最先受降雨影响。降雨前,路基含水率相对恒定;降雨入渗后,路基不同深度截面含水率都表现为先迅速增加,而后趋于稳定,最后缓慢减小。相同深度截面,挖方路基含水率波动幅度显著大于填方路基。对于挖方、填方路基,数值仿真所示含水率变化规律与实测结果较为类似,有限元分析软件可较好地预测路基含水率空间分布。

In order to explore the spatial distribution of subgrade water content under rainfall infiltration conditions,TDR moisture sensors were embed in different depth sections of the subgrade to continuously observe the change of water content,and numerical simulation analysis was conducted through finite element analysis software to compare the difference between the measured value and the simulation value.The results show that the influence of rainfall infiltration on subgrade water content is lagging,and the top surface of subgrade is affected firstly.The water content of subgrade is relatively constantbefore rainfall,and he moisture content of different depth sections of subgrade first increases rapidly,then tends to be stable,and finally decreases slowly after the rainfall.The fluctuation of water content of the excavated subgrade is significantly greater than that of the filled subgrade even at the same depth section.Finite element analysis software can better predict the spatial distribution of subgrade moisture content since the change law of water content shown in numerical simulation is similar to the measured results for the two types of subgrade.