交通荷载下土工格栅加筋软土地基的变形特性

Deformation Characteristics of Geogrid Reinforced Soft Soil Foundation under Traffic Loading

应用有限单元法对交通荷载作用下的(软土)地基进行隐式动力分析,再基于地基应力响应分析和变形响应分析,研究了土工格栅加筋减小交通荷载引起的地基累积塑性变形的机理.结果表明:路堤高度为1m左右时,在交通荷载作用下,地基会产生显著的累积塑性变形;土工格栅加筋改善地基表面的最大压应力分布,减小传递到地基表面的剪应力;土工格栅加筋降低了地基上部由交通荷载引起的动偏应力,从而致使地基的累积塑性变形明显减小;随着路堤高度的增加,由交通荷载引起的地基累积塑性变形迅速减小,加筋效果相应下降.

Soft soil foundation under traffic loading was modelled by implicit dynamic FEM（finite element method）.Based on stress response analysis and deformation response analysis,the mechanism of the decrease of cumulative plastic deformation of soil foundation by geogrid reinforcement was investigated.Analysis result shows that the cumulative plastic deformation of soil foundation with about 1 m embankment thickness de velops rapidly under traffic loading.Geogrid reinforcement can improve maximal compressive stress distribution,and decrease shear stress on the surface of soil foundation.Geogrid reinforcement can diminish dynamic deviator stress on the upper part of soil foundation induced by traffic loading,with the result that it decreases the cumulative plastic deformation of soil foundation obviously.The cumulative plastic deformation decreases distinctly with the increase of the embankment thickness,and the effect of reinforcement is descending accordingly.