Flexible geogrids installation damage under various conditions

An on-site full-scale installation damage test of PVC-coated PET flexible geogrids was performed. Two different strength geogrids and five different typical soils were selected for the test. A series of single rib strength tests (GRI-GG1) and in-isolation junction strength tests (GRI-GG2) was performed to evaluate the strength of reduction due to the installation procedure in the study. The results of the study indicated that installation damage to a flexible geogrid is a function of grain size distribution and angularity of backfill material, compaction effort and lift thickness, and type and weight of construction equipment. Based upon the test results, the tensile strength retained for flexible geogrid placed within fine grain soil, sandy soil, gravel with some fine soil, and crushed stone gravel are 89% to 94%, 83% to 88%, 83% to 87%, and 70% to 80%, respectively. The partial factor of safety for installation damage is significantly related to soil type and varies from 1.05 to 1.40.