复合填料一维冻胀量数值模拟分析

Abstract

A composite backfill was formed by mixing waste foundry sand, fly ash, expanded polystyrene (EPS) beads, cement and water in designated proportions. Inclusion of EPS beads can reduce or eliminate frost heave and thaw settlement, and thus favor the use of the composite backfill as road base and subgrade materials in seasonal frost areas. A one-dimensional frost heave model was established based on the current moisture-heat coupling model. The model is able to take into account the elastic-plastic behavior of EPS bead and its effect in buffering the frost heave taken place within the mass of composite backfill. The results given by the model are in a good agreement with the test results achieved from a previous companion study, which validates the use of this model in the prediction of frost heave of engineering works in seasonal frost areas. = 复合填料是以废铸砂、粉煤灰、聚苯乙烯颗粒(EPS)、水泥和水为原料,拌合后形成的一种轻质填筑材料。其中,EPS颗粒含量适当时,能减少或消除复合填料的冻胀和融沉,可作为季节性冻土区的路基填料。假设复合填料中除EPS颗粒外的骨料颗粒、孔隙冰为刚性介质,同时考虑EPS颗粒变形和填料孔隙变形对复合填料冻结过程的影响,在已有的冻土水热耦合分离冰模型的基础上,得到考虑EPS颗粒变形影响的饱和填料一维冻结水热耦合控制方程,进而预测填料的冻胀量。与室内模型试验结果对比表明,本文模型可用于该种具有弹性颗粒复合填料的冻胀量模拟,为工程中冻胀量预测提供依据。