台阶宽度对加筋土挡墙垂直应力的影响研究

Effect of offset distance on vertical stresses in geosynthetics reinforced soil retaining wall

为了研究台阶式加筋土挡墙平台宽度对下墙墙体垂直应力大小及分布的影响,进行3组不同平台宽度的台阶式加筋土挡墙室内模型试验。试验结果表明:台阶式加筋土挡墙基底垂直应力随着填土高度的增加而增大,最大值出现在墙面板附近;随着墙间台阶宽度的增加,基底垂直应力沿筋长的分布形式由"V"字形逐渐过渡到倒"S"形;过大的台阶宽度对双级加筋土挡墙基底垂直应力的减载效果不明显;修正的FHWA方法和修正的Gray弹性解方法可较为准确计算基底垂直应力;随着墙顶荷载加载位置距墙面板距离的增加,基底垂直应力逐渐减小;墙顶施加荷载后下墙筋材中后部垂直应力增长较大,而拉筋始端垂直应力变化较小。

In order to study the effect of the offset distance on the magnitude and distribution of vertical stress of tiered geosynthetic reinforced soil wall,a series laboratory tests on geosynthetic-reinforced soil（GRS） two-tier wall models with three offset distances were carried out. The test results indicated that the vertical stress at the bottom increased with the wall height rising and that the maximum value appeared nearby the wall. With the increasing of offset distance,the distribution of the vertical stress along the reinforcement was evolved from V-shape to inverted S-shape. The effect of overlarge offset distance on the vertical stress at the bottom of the two-tier geosynthetic reinforced soil wall was not obvious. The vertical stress at the bottom of the geosynthetic reinforced soil wall was calculated quite accurately with the modified FHWA method and modified Gray elastic solution. The vertical stress in the lower wall decreased with the increasing of the load location distance to the upper tier face. After the loading was applied on the upper tier,the vertical stress at middle and back reinforcement increased,but at the front of reinforcement changed little.