网孔尺寸对土工格栅-无黏性土界面特性的影响

摘要

Geogrids have been adopted more and more widely in the engineering with reinforcement of high embankment because of its unique mesh structure and better effects of reinforcement. The calculation of geogrid reinforcement is often carried out according to the plain strain in two⁃dimensions, which does not consider the influence of geogrid mesh size on interface properties when determining the interfacial strength parameters, so its accuracy and rationality should be studied. Using the standard sand with the same grain size (cohesionless soil) as the filling material, the paper studies the influence of mesh size of geogrid on the interface properties through large⁃scale shear experiments and 3D numerical methods. It shows that the influence is significant. The larger the mesh size, the higher the corresponding strength parameters of the interface and the more significant the effects of the friction reinforcement. However, the corresponding requirement on geogrid material is also higher;otherwise the tensile strength requirement cannot be satisfied.%土工格栅加筋体的计算常常按二维平面应变问题进行，在确定界面强度参数时无法考虑土工格栅网孔尺寸对界面特性的影响，其准确性及合理性值得研究。以单一粒径的标准砂（无黏性土）为填料，通过大型剪切试验和三维数值模拟研究了土工格栅网孔尺寸对其界面特性的影响，结果表明：土工格栅-土界面特性受土工格栅网孔尺寸影响明显，网孔尺寸较大的土工格栅对应的界面强度参数更高，摩擦加筋作用更明显，但是要求土工格栅材料的轴向拉力也更高，否则不能满足抗拉强度的要求。