土工合成材料加筋土界面渐进拉拔行为的理论解析

A simple analysis solution to predict progressive pullout behavior of geosynthetics in reinforced soil

随着国民经济的发展,土工合成材料被广泛应用于边坡和挡墙等实际工程中。筋土界面的界面摩阻力是设计中的关键考虑因素。文中主要分析加筋土界面拉拔状态下的渐进破坏行为,将拉拔过程分成三个阶段:纯弹性阶段,界面的剪切应力与剪切位移呈弹性关系;弹—塑性阶段,通过一个临界点划分弹性区和塑性区;完全塑性阶段。并且给出了各个阶段的拉力、位移和剪应力的解析解。最后通过两组拉拔试验结果与解析计算的比较分析验证了该模型的准确性。对筋土界面摩阻力分布规律进行了详细研究,深入地分析了加筋长度、筋材的弹性模量、剪切刚度和塑性区间长度等因素对加筋土界面的渐进拉拔行为的影响。

With the development of the economics,the geosynthetics are widely used in practical engineering like slope and retaining wall.The interface frictional resistance force of the reinforced soil interface is a critical aspect in the design process.In this paper,the progressive failure behavior of the reinforced soil interface under the pullout condition is mainly investigated,pullout process is divided into three phases.Pure elastic phase during which follows a elastic relation between the shear stress and shear displacement of the interface;elastic-plastic phase during which a transition point divide the elastic and plastic zones;and fully plastic phase.The analytical solution of the tensile force,shear stress and displacement in all stages is given.The results from analysis method agree well with pullout tests.In addition,the regularity of distribution of the frictional resistance is investigated in detail and the influence factors are analyzed,including the length of the reinforcement,elasticity modulus of the geosynthetics,shear stiffness and length of plastic zone.