Durability and long-term performance of Tensar* polymer grids for soil reinforcement

Abstract

Tensar polymer grids (geogrids) are oriented integral polyolefin structures, specifically developed to reinforce and stabilize soil in civil engineering works for which there is a design life of 100 years or more for buried materials. It is confirmed, from the results of work by others, that their composition and structure give these geogrids good resistance to biological attack and detrimental aging in such applications. Environmental stress cracking and outdoor weathering are discussed in detail, and results of specially commissioned tests in both areas are presented. Methods used to establish a 120-year load-bearing capacity are explained. It is seen that currently the performance of a structure reinforced by Tensar geogrids is determined by soil strain, not reinforcement strength. Any damage that may be caused to the geogrids must be taken into account at the design stage. Large-scale tests carried out to determine the magnitude of such damage are described, and the results presented.MST/591