考虑裂隙非饱和膨胀土边坡入渗模型与数值模拟

包含裂隙的非饱和膨胀土中的渗流具有随时间变化的特性。采用常规试验测定非饱和膨胀土膨胀时程曲线，定量地描述了膨胀土中裂隙在入渗过程中逐渐愈合的特征, 建立了考虑裂隙的非饱和膨胀土边坡入渗的数学模型；用有限元数值模拟方法分析了边坡地形、裂隙位置、裂隙开展深度及裂隙渗透特性等对边坡降雨入渗的影响。结果表明, 坡上位置的裂隙对边坡入渗影响较大；裂隙对边坡入渗的影响随裂隙深度的增大而增大，且存在一最大的影响程度；裂隙的存在加快了膨胀土的入渗速率；考虑裂隙随入渗而愈合时, 入渗达到平衡的时间有所延长。

Numerical model and simulation of expansive soils slope infiltration considered fissures

The seepage in unsaturated expansive soils contained fissures is a time-depended process. Time-travel expansive curves determined by normal expansive swelling test are used to describe the healing of fissure during the infiltration process. Numerical model for unsaturated expansive soils slope infiltration is set up considered fissures influence. Finite element simulation is used to analyze the influences of fissures’ position, depth and seepage characteristics on slope rainfall infiltration. The results show that the fissures on the upper part of slope make greater influence. Deeper the fissures, greater influence on slope infiltration. While, the influence has a maximum extend. Fissure existence accelerates the infiltration rate. Longer duration is needed to reach balance state while considered the healing of fissures with seepage process.