防渗对降雨引起的膨胀土路基渗流场的影响

采用有限元软件ABAQUS对由降雨引起的城市道路路基渗流场进行数值模拟。在降雨量一定的情况下,根据采用和不采用防渗措施时路基中饱和度和含水量的分布,分析降雨强度、土工膜防渗以及防渗深度对路基中水分分布及迁移的影响,并探讨土工膜防渗对控制城市道路膨胀土路基胀缩变形的意义。分析结果表明:降雨强度越低,雨水入渗引起的路基含水量变化量越大,沿路基横断面分布越不均匀;土工膜防渗以后,路基受降雨的影响明显下降,随着防渗深度的增加,降雨对路基中含水量分布的影响显著减小;防渗可控制降雨引起的膨胀土路基膨胀变形的发展。

Influence of Anti-seepage on Seepage Field of Expansive Soil Subgrade Induced by Rainfall

Seepage field of urban road subgrade induced by rainfall was numerically modeled by finite element method ABAQUS .For given rainfall ,based on distribution of saturation degree and water content in subgrade with and without anti‐seepage measures ,influence of rainfall intensity ,anti‐seepage of geomembrane and the impermeable depth on distribution and migration of moisture in subgrade was analysed .The meaning of anti‐seepage of geomembrane on the control of swell‐shrink deformation of expansive soil subgrade of urban road was also discussed .Analytical results show that the lower the rainfall intensity ,the greater the variation of water content in subgrade due to rainfall infiltration is ,and the more uneven the distribution of it along cross section of subgrade is .With anti‐seepage of geomembrane ,the influence of rainfall on subgrade is obviously decreased .As the depth of anti‐seepage is increased ,the influence of rainfall on the distribution of water content in subgrade is significantly reduced .Anti‐seepage can control the development of swelling deformation of expansive soil subgrade subjected to rainfall .