加筋方式对斜坡软弱地基高填路堤稳定性影响

Influence of geogrids layout on the stability of high embankment with weak slope foundation

采用加筋土是解决斜坡软弱地基高填方工程变形与稳定性问题的有效措施之一。为了深入揭示加筋方式对此类问题的影响规律,依托衢宁铁路屏南车站站场斜坡软基高填方工程,基于实际工程地质条件,通过三维有限差分数值模拟方法,分析了不加筋、只加长筋、只加短筋及长短筋组合共4种加筋方式对高填方边坡变形与稳定性的影响特征。结果表明,受桩基托梁挡墙影响,加筋方式对路堤变形影响较小,但对路堤边坡稳定系数与潜在滑面影响显著;在斜坡软弱地基条件下,长短组合加筋与只加长筋比不加筋时的路堤稳定系数均提高30.0%,具有良好的加筋效果。

The soil with geogrids is one of the effective measures to solve the deformation and stability problems for high embankment on weak slope foundation. Based on the high embankment on weak slope foundation in Pingnan station of Quzhou-Ningde railway, the three-dimensional finite difference numerical simulation model is used to study the problems. There are four kinds of reinforcement measures used for the embankment which include with the non-reinforced, with only long geogrids, with only short geogrids, and with the combination of long and short geogrids. The computation results show that geogrids has no obvious effect on the deformation of the embankment under railway loads due to the constraint effect of pile- supported gravity wall on the embankment, but the geogrids layout has great influence on the factor of safety and the potential sliding surface of the embankment. Under the condition of weak slope foundation, the safety factors of the embankments with the combination of long and short geogrids and with only long geogrids are individually 30% more than that without any geogrids. The reinforcement effect of the geogrids on the high embankment is favourable in practice.