排水带加速黄土路基固结沉降的数值模拟研究

Numerical Simulation Study on Drainage Belt Accelerating Consolidation Settlement of Loess Subgrade

【目的】路基填筑过程中产生的沉降及其工后沉降,将会直接影响工程施工质量、工期和后期维护费用。【方法】为探究排水带在三门峡黄土路基的作用效果,运用Settle 3D软件建立数值模型,分析自然、降雨工况下排水带间距对原状和重塑黄土路基固结沉降的影响。【结果】研究结果表明:降雨工况下的沉降量和沉降速率较自然工况下的大,这种现象在原状路基上最为明显;排水带能够显著加快黄土路基的沉降速率,其效果随着排水带间距的缩短而增强;排水带间距由8.0 m缩短为2.0 m时,排水带改善黄土路基的效果达到稳定,间距在0.5~2.0 m之间变化时,其改善效果并不明显。【结论】针对三门峡黄土路基工程,建议排水带间距可选择为2.0 m。

[Purposes] The settlement generated during the subgrade filling process and its post-construction settlement will directly affect the construction quality,construction period and subsequent maintenance costs.[Methods] In order to explore the effect of drainage belt on Sanmenxia loess subgrade,a numerical model was established by using Settle 3D software to analyze the influence of drainage belt spacing on the consolidation settlement of undisturbed and remolded loess subgrade under natural and rainfall conditions.[Findings] The results show that the settlement and settlement rate under rainfall conditions are larger than those under natural conditions,and this phenomenon is most obvious on the undisturbed subgrade.Drainage belt can significantly accelerate the settlement rate of loess subgrade,and its effect increases with the shortening of drainage belt spacing.When the spacing of drainage belt is shortened from8.0 m to 2.0 m,the effect of drainage belt on improving loess subgrade is stable,and the improvement effect is not obvious when the spacing is between 0.5 m and 2.0 m.[Conclusions] For the Sanmenxia loess subgrade project,it is recommended that the drainage belt spacing be 2.0 m.