针对加筋土挡墙中拉筋水平和垂直间距、筋带宽度和拉筋长度的合理布设问题,根据拉筋所受土压力相等的等土压应力面积法,提出了拉筋水平等间距、垂向沿埋深逐层加密的布置方式及相应的计算式;采用砂箱模型试验,以墙体处于极限稳定状态下的最少用筋面积为条件,探讨了加筋土挡墙的合理布筋方式。试验分析表明:采用与土压力沿深度逐渐增大相适应的拉筋“上疏下密”布置形式可实现筋带均衡受力,在“窄筋密布”的条件下具有更好的稳定性且用筋量更少;与墙后填土潜在破裂楔体呈上宽下窄形状相适应的筋带“上长下短”布置方式稳定性优于“上下等长”布置;采用“窄筋长布”的方式较“宽筋短布”能增加筋带有效锚固面积,提高挡墙稳定性。

The rational layout of reinforcement in reinforced soil retaining wall is discussed by using sand box model test. The horizontal and vertical spacings, width and length of reinforcement in the prerequisite of minimum reinforcement area under limit stable state are researched. According to the method of equal soil pressure, the layout of reinforcement which is increasingly denser in vertical direction with equal horizontal spacing is put forward, and the corresponding calculation formula is presented. Analysis shows that the layout pattern “sparse in the upper part and dense in the lower part” which is consistent with the increasing soil pressure along depth leads to a balanced force on the reinforcement, and this layout pattern (narrow geobelts distributed densely) requires less amount of reinforcement and achieves better stability; while the layout with long geobelts in the upper part and short geobelts downwards which adapts to the shape of backfill potential rupture wedge (wide in the upper part and narrow in the lower part) is prior to the layout with geobelts of equal length; and moreover, narrow and long geobelts could increase the effective anchorage area and improve the stability of retaining wall compared with wide and short geobelts.