Product PerformanceEvaluation of combination effects of installation damage and creep behavior on long-term design strength of geogrids

In this study, we compared the combination effect of creep and installation damage (represented by the reduction factor, RFDCR) to the individual effects of creep (represented by the reduction factor, RFCR) and installation damage (represented by the reduction factor, RFID) on the long-term design strength of geogrids. To evaluate the reduction factors of creep and installation damage, 12 types of geogrids, viz. woven PET/PVC-coated, warp-knitted PET/PVC-coated, HDPE uniaxially drawn and PET strip-razor-bonded geogrids were used, and three kinds of soil, viz. two types of granite weathered soil with a controlled particle size and gravel (25 mm) were compacted. Then, a site burial test was performed to measure the installation and creep induced damage. Creep was measured on both the as-received and buried samples. It was concluded that the manufacturing process of the geogrid and the dmax of the soil particles affect the RFID and RFCR values. The combination effect of installation damage and creep on the long-term allowable tensile strength is smaller than that obtained using RFID and RFCR individually, with the difference being about 4.3-20.1% for the woven geogrid and about 0-2.2% for the uniaxial geogrid.