加筋土挡墙拉筋轴向应力分布规律研究

基于剪力滞模型基本原理对加筋土挡墙筋土作用机理进行了研究。根据拉筋轴向应力是由拉筋周围土体发生剪切位移而产生，紧邻拉筋周围土体仅受剪应力作用的假定，将加筋体单元中土体分为内、外两层，建立了拉筋轴向受力平衡方程，推导出了加筋土挡墙拉筋轴向应力特解。理论分析表明，加筋土挡墙中拉筋轴向应力沿拉筋长度L呈非线性分布，且在x≤L/2时出现一个峰值；当水平拉筋沿筋长方向出现凹陷或凸起时，在该位置将产生拉力峰值。该研究成果合理解释了加筋土挡墙中拉筋轴向应力出现多个峰值以及越靠近墙底部潜在破裂面位置越接近墙面板的原因。

Distribution rules of axial stress of reinforcement in reinforced earth retaining wall

Based on the shear-lag model, the interaction mechanism between reinforcement and soil matrix in the reinforced earth retaining wall is analyzed. A hypothesis is proposed that the axial stress in the reinforcement comes from the shear displacement of the surrounding soil matrix and that the surrounding soil matrix will bear the shear stress only. The soil matrix in reinforced soil unit is separated into outer layer and inner layer. The stress equilibrium differential equation for the reinforcement is established, and a formula which describes the distribution rules of the axial stress in reinforcement is brought forward. According to the theoretical analysis, the proposed formula can show non-linear distribution, and a maximum value point xof the axial stress in the reinforcement is x≤ L/2 (Lmeans the reinforcement length). The axial stress in the reinforcement of reinforced earth retaining wall will have only one maximum value when the reinforcement is horizontal, and multi-maximum values will arise when the reinforcement is concave or convex along the reinforcement length. The reasons of the occurrence of multi-maximum values of reinforcement axial stress in reinforced earth retaining wall and the phenomenon of the potential rupture surface close to the wall panel near bottom wall can be explained according to the research results.