Simulation of Unconfined Compression Tests of Geogrid-Reinforced Granular Soil

Abstract

In order to analysis of the mechanical properties of geogrid-reinforced granular soil, a simulation model of unconfined compression tests is proposed based on the laboratory tests conducted before by the author. This numerical method, after modified by the laboratory test data, is adopted to carry out a simulation of unconfined compression tests using large specimens of geogrid-reinforced granular soil. Each large specimen, with the diameter of 175cm and the height of 300cm, varies in reinforcement spacing of 30 cm, 37.5cm, 50 cm or 75 cm. For comparison, the same simulation test is also demonstrated for the granular soil without geogrid. A series of simulated compression stress-strain relationship curves are presented, on which a detail analysis is carried out. The following conclusions are obtained: (1) The geogrid-reinforced granular soil is a strain-hardening mass if the reinforcement spacing is less than about 50 cm. (2) While the reinforcement spacing is smaller enough, there is no sliding at the geogrid-soil interface and, therefore, the geogrid-reinforced granular soil may be taken as a composite material.