Mechanical behavior of sand reinforced with conventional and NPR geogrids: A numerical study on structural influence

As engineering infrastructures face increasingly complex loads, conventional geo-structures demonstrate inadequate strength and energy-absorbing capacity when subjected to seismic events. To address this critical gap, this study introduces the development of a novel geogrid with negative Poisson's ratio (NPR) effect, which significantly improves the strength and energy absorption efficiency during sand deformation. The finite element analysis was carried out to compare the mechanical performances of sand reinforced by the NPR geogrids and the conventional geogrids with square shape. The biaxial shear tests under static load and periodic dynamic load were simulated. It is found that the NPR geogrids can effectively increase the shear strength of sand under compression, through enhanced shear dilation in dense sand and increased compaction in loose sand. Furthermore, this paper explores the influence of NPR geogrid on soil behavior by examining their effects on Young's modulus and protrusion angle, where it is found that the shear strength increases with an increase in the Young’s modulus, while it firstly increases and then decreases with the increasing protrusion angle.