加筋土结构中筋材拉拔力的分布规律研究

Stress distribution of reinforcement of reinforced soil structures under drawing force

分析了加筋材料在拉拔试验条件下,筋材所受到的拉力、剪应力、应变之间的关系,利用筋土界面间存在的抗剪刚度系数G,建立起了与材料拉伸模量E r和G有关的拉拔影响系数,从而推导出拉力沿筋材分布的公式和各点筋土的相对位移公式。通过与已有的试验数据相对比,证实该公式的可行性。分析了拉力在筋材上的传播规律和对筋材拉拔力分布的影响,表明用能综合反映压应力、摩阻力、土体性质等多种因素对筋材拉力的影响。在加筋土结构中,筋材位移不是很大时,采用该公式能较好地估算筋材各处的拉力。

The relationship among tension, shear stress and strain of geosynthetics is analyzed by means of pull-out tests. By using the shearing resistance stiffness coefficient G existing at the reinforced soil interface a pull-out coefficient α that relates to the tensile modulus Er and G, is established, and thus the formulas for stress distribution and the relative displacement along the geosynthetics are derived. The feasibility of the formulas is confirmed by comparing with the existing experimental data. Then the stress transmission way of geosynthetics with the increase of tension and the influence of α on stress distribution of geosynthetics are analyzed. It is shown that α can be better used to reflect the influences of many factors such as stress, friction and soil properties on the tension of geosynthetics. In the structure of reinforced soil, the proposed formulas are better to estimate the tension of geosynthetics under small displacement.