差异沉降对加筋土挡墙筋带内力与变形的影响

采用正交设计进行加筋土挡墙缩尺模型试验。通过对筋带延伸率、筋带密度、筋带与面板连接方式三个可变因素的二水平4组试验,研究墙后填土与墙面板之间的差异沉降对筋带变形的影响。结果表明,差异沉降导致筋带不再保持原来的水平位置,其竖向变形可以用指数曲线描述。应用弹性薄膜理论与筋土相互作用耦合方程对筋带变形及内力进行的分析表明,差异沉降导致的筋带应变由水平位移和竖向挠度共同引起,该应变比常规设计中筋带应变大,将导致筋带受力条件恶化,挡墙安全度降低。

Effect of Differential Settlement on the Tension Force and Deformation Behavior of Reinforcements for Reinforced Earth Retaining Wall

Orthogonal test method is adopted for the reinforced earth retaining wall reduced model tests. Four series tests were performed to measure the effect of differential settlement between facing and backfill on the deformation behavior of reinforcements, with three alterable factors vary on two levels, namely, the extensibility and the density of the reinforcements, the connection mode of the reinforcement and the facing. The tested data indicate that the differential settlement makes the reinforcement no longer keep its original horizontal position and its vertical deformation can be well described by exponential curve. Equations that couple the elastic membrane theory with the interaction between the reinforcement and the soil are employed to analyze the tension force and deformation of reinforcements. It shows that the differential settlement induces the strain of the reinforcement is bigger than that of routine design, which come from both the horizontal displacement and the vertical deflection. It would worsen the force condition of the reinforcement and debase the safety factor of reinforced retaining wall.