为了研究砂卵石填料加筋土挡墙筋土间荷载传递规律,将加筋土视作以土体为基体,筋带为增强的复合材料,在轴向受力情况下,将拉筋周围土体分为界面层和加筋有效影响层。基于加筋有效影响层内由筋带产生的附加剪应力沿法向呈线性衰减的假设,修正了传统剪力滞后模型,建立起加筋带平衡微分方程,解得加筋土挡墙筋带轴向应力分布规律解析解。通过与拉拔试验数据对比,发现理论推导与试验结果比较吻合。研究结果表明:砂卵石填料加筋土挡墙拉筋应力沿长度l方向呈先增大后减小的类抛物线形状,且峰值出现在<l/2处;紧邻拉筋部分土体出现带状加筋有效影响层,且附加剪应力在该土层内沿法向线性衰减。

In order to study the rules of load transfer between reinforcement and soil in reinforced earth retaining wall with sandy cobble, the reinforced soil was considered as composite materials in which soil and reinforced belt was regarded as matrix and reinforcing material, respectively. The soil around the reinforcement was separated into the interface layer and the effective influence layer under axial load. Based on the hypothesis that the additional shear stress produced by the reinforcement turned to linear attenuation in the effective influence layer, we modified the traditional shear-lag model and established the stress equilibrium differential equation for the reinforcement, from which attained the axial stress analytical solution of the reinforcement. After comparing with the drawing test data, we found that the theoretical derivation was in accordance with the test results. According to the research, the axial stress of reinforcement increases firstly, and then decreases along the reinforcement length l, which shows parabolic-shaped distribution; and a maximum value appeared at a distance less than l/2 from the wall. The soil close to the reinforcement appeared banded effective influence layer, and the additional shear stress caused by the reinforcement in the effective influence layer turned to attenuate linearly along the normal direction.