Experimental study on visco-elastic constitutive relationship and its parameters for geogrids

Geogrids are used as reinforcement materials widely in geotechnical and civil engineering fields. In this paper, a series of comparative tests on creep behavior of specific geo0grids are conducted in the laboratory under different combinations of loading levels and environmental temperature. Based on the test results, comparative analyses are made to study long-term behaviors of isochronous load-strain curves, creep curves and relaxation curves for the specified geogrids. Furthermore, a constitutive model based on theory of visco-elasticity and tests results is proposed for geogrids and a rational procedure is presented in detail for determining the relevant parameters of the proposed model. Finally, the effect of tests temperature on model parameter values is investigated.