注浆体对土钉受力特性的影响研究

Effects of grouting on mechanical properties of soil nailing

基于土钉抗拔力学模型的解析解,结合现场土钉抗拉试验工程实测数据,分析了水泥注浆体弹性模量Eg及钉土剪切变形系数K的变化对土钉受拉力学特性的影响。结果表明,随着Eg的增大,最大荷载下钉头位移逐渐减小,浅部钉土间相对位移和剪力有所减小,而深部则有所增大。Eg越大,钉土间相对位移和剪力沿钉身的变化越小,各部分侧阻分布趋于均匀。随着K的增大,最大荷载下土钉沿钉长各处的相对位移均减小,且减小比率逐渐降低,注浆对土钉的影响逐渐趋弱。相同变化率下K对土钉荷载-位移曲线的影响要大于Eg,而对钉土间剪力的影响则不及Eg的影响大。

Based on the analytical solution for soil nailing tension model and the field measured data of soil nailing tensile test,the influences of elastic modulus of cement grout Eg and shear deformation coefficient of soil nailing K on the mechanical properties of soil nailing are analyzed. The results show that the displacement of nail head under the maximum loading decreases as Eg increases.With the increase of Eg, the relative displacement and shear force between soil and nail, decrease in the shallow part of the nail body,and increase in its deep part, respectively. Furthermore, the variations of relative displacement and shear force between soil and nail along the nail body direction become much smaller with the increase of Eg, resulting in more homogeneous distribution of side friction resistance along the nail body. As K increases, the relative displacement between soil and nail under the maximum loading decreases and the variation of relative displacement along the nail body direction becomes much smaller, indicating the effect of grouting on soil nailing gradually becomes marginal. With the same change rate of K and Eg,the influence of K on the load-displacement curve of soil nailing is greater than that of Eg, while the influence of K on the shear force between soil and nail is lower than that of Eg.