软基加筋路堤的机理分析及数值模拟

Study and Numerical Simulation of a Reinforced Earth Embankment over Soft Soils

采用数值模拟计算对软基筑堤变形规律和机理进行剖析。结果表明:铺设加筋材料后路堤及其地基土水平位移得到有效控制,且土体固结时回笼收缩幅度明显增加。加筋能使路基沉降更加均匀,但对总沉降的影响较小。在路堤填筑阶段,加筋路堤较无筋路堤的地基超静孔压显著增加,后续随土体固结,孔压消散,两者趋于一致。加筋后,路堤整体稳定性有较大的提升,极限状态下加筋前后的滑弧有明显区别,这与筋材特性、筋土界面特性以及土体物理力学参数等条件相关。堆填速率对无筋路堤影响较大,而设置加筋材料后,在满足筋材强度和界面强度的前提下,路堤可快速填至设计高度。

The finite element method w used to analyze the deformation development in the process of a reinforced earth embankment over soft soils.The results show that the embankment reinforcement can effectively control the lateral deformation of soft soil,improve the ability of“contracting”of horizontal displacement in consolidation stage,uniformize the embankment settlement.In the embankment filling stage,the excess pore pressure in the underlying soft soil in the reinforced earth embankment is obviously higher than that of underlying the unreinforced embankment.However,with the consolidation of soft soil gradually tends to be consistent between the reinforced and the unreinforced embankments.The safety factor of embankment is obviously improved after the soil reinforcement.The failure modes are different between the reinforced and unreinforced embankments due to the characteristics among the soil reinforcement,soil-geogrid interface and embankment soils.The embankment filling rate has a significant effect on the unreinforced embankment.If the reinforced earth is placed in the embankment,construction rate can be improved.