Analysis of mutual dependence and connectivity of reduction factor on long-term performance and durability of geogrids

摘要

Damage of geogrids can be occurred by equipment or careless working and can be caused installation failure to effect on the long-term stability of structures. Both individual effect and combined effect of the factors were observed. For estimating allowable tensile strength considering reduction factor over the short-term tensile strength of geogrids, it has a limit not to consider interaction force between reduction factors. Junction strength comes to be reduced by installation damages or chemical degradation in the same way as tensile strength. Single junction test method cannot properly test damaged samples and shows large deviations as it does not consider scale effect. In this study, (a) reduction factors to affect the long-term performance of geogrids were revaluated under various conditions and (b) accurate long-term allowable tensile strength was calculated considering interrelation among reduction factors. Reduction factor by creep after installation damage and chemical resistance tests showed lower than that of calculated by GRI GG-4. After the installation damage and chemical resistance tests, reduction factor of junction strength was less than that of tensile strength. Finally, to consider the damage of geogrids that inevitably occurs upon construction on site, a proper model for the construction conditions on site must be applied.