土工格栅−建筑渣土界面摩阻特性试验研究

为了研究格栅?建筑渣土的界面摩阻特性，进行了4种不同级配的建筑渣土与3种格栅（两种双向格栅和一种三向格栅）的界面直剪摩阻试验。试验表明，格栅?建筑渣土界面摩阻应力和单位剪位移关系均可用双曲线模型表示；界面摩阻强度与垂直压力呈线性关系；格栅类型、填料级配等决定筋?土界面摩阻特性，其中格栅的拉伸模量影响最为明显；格栅的拉伸模量越大，筋?土界面似摩阻系数越大，界面似黏聚强度越大。似摩阻系数不受渣土级配影响，由格栅类型决定。似黏聚强度既受到渣土级配影响又与格栅特征有关，在本研究的4种级配渣土条件下，对于三向格栅?渣土界面，中、细砾为主的级配渣土的似黏聚强度最大，而对于双向格栅?渣土界面，粗砾为主的级配渣土的似黏聚强度最大。剪切前后渣土颗粒级配变化不明显，可忽略其影响。

Experimental study of the frictional resistance characteristics of geogrids and construction residue interface

To study the frictional resistance characteristics of geogrids and construction residue interface, a series of direct shear tests were conducted on the interface between four different gradations of construction residue and three types of geogrids. The results showed that the relationship between the unit shear displacement and the frictional resistance of the interface between geogrid and construction residue could be expressed by hyperbolic model. The strength of the frictional resistance at the interface increased linearly with the vertical pressure. The structure characteristics of geogrid and the gradation of construction residue determined the frictional resistance characteristics of the grid-residue interface, among which the influence of the tensile modulus of geogrid was the most obvious. The higher the tensile modulus of geogrid was, the greater the quasi friction coefficient and the quasi cohesive strength of the interface were. The quasi friction coefficient was not affected by the gradation of construction residue, but determined by the structure characteristic of geogrid. The quasi cohesive strength was not only affected by the gradation of construction residue, but also related to the structure characteristic of geogrid. For the interface between triax-geogrid and residue, the graded construction residue dominated by medium and fine gravel had the greatest quasi cohesive strength but for the interface between biaxial-geogrid and residue, the graded construction residue dominated by coarse gravel had the greatest quasi cohesive strength. Before and after shearing, the change of the particle gradation of construction residue was a little, so its influence could be ignored.