本文介绍了一个考虑非饱和土水-力耦合行为的本构模型,并通过二次开发嵌入有限差分程序FLAC,根据加载和湿化路径的三轴试验数据对本构模型进行了验证。利用验证的非饱和土本构模型模拟路堤填料,研究了非饱和土加筋路堤在降雨条件下的湿化变形行为,同时对比研究了筋材对路堤湿化变形的影响。研究结果表明：筋材在未加筋区几乎不产生影响,但筋材能有效减小加筋区土体单元的体积应变和剪应变。筋材对路堤中线附近的未加筋区的顶面沉降几乎不产生影响,但是能有效减小路肩处的顶面沉降和路堤边坡的侧向位移。筋材长度越长,其对减小路堤的顶面沉降和路堤边坡的侧向位移效果越好,路堤内部的潜在破坏面距坡面越远。

A constitutive model that considers the hydro-mechanical coupled behavior of unsaturated soils was introduced and implemented in the finite difference program FLAC. Triaxial test data involving loading and wetting paths were used to validate the constitutive model implemented in FLAC. Using the validated constitutive model to simulate the embankment fill, the deformation behavior of unsaturated reinforced embankments subjected to rainfall infiltration was investigated. The influence of geosynthetic reinforcement on the wetting-induced deformations of embankments was investigated. The results show that the reinforcements have negligible impact in the unreinforced zone. However, the reinforcements can effectively reduce the volumetric strains and shear strains of the soil elements in the reinforced zone. The reinforcements have a negligible effect on surface settlement in the unreinforced zone near the centerline of embankment but are effective in reducing surface settlement at the shoulder and lateral displacements of embankment slope under rainfall. The longer reinforcements are more efficient in reducing surface settlements of embankment and lateral displacements of slope and could also increase the distance between the slope surface and the potential failure surface.

TU473.1

国家自然科学基金（No. 52078392、52078236）；国家重点研发计划（2022YFC3080400）