Abstract:

The characteristics of the interface between the soil and the geogrids are lack of study. To make a contribution to this respect, applying the uniaxial and biaxial geogrids and the soil weathered from the expansive marlite in Xinxiang section of the middle route of South to North Water Transfer Project(SNWT), a giant laminatedring type shear test apparatus with soil filling of dimensions of 600×600×600 mm was adopted to do a series of pullout tests to investigate the ralations of the average friction versus the relative displacement and the interface strength characteristics under different water contents and dry densities of the expansive soil. An ideal elastoplastic model was used to simulate the interface behavior, the interface strength curves were expressed as the linear functions, and the parameters were analyzed based on the average friction and the average relative displacement of the interface between soil and geogrids. Furthermore, the feedback analysis of the interface parameters was discussed when the progressive yield occured at the interface.

Key words: engineering geology, geogrid, compacted expansive soil, interaction, interface model, south to north water transfer project (SNWT)