Reliability analysis of geogrid installation damage test data in Japan

The paper reports the results of the analysis of field installation damage tests carried out on geogrid soil reinforcement products used in Japan. The data are taken from Public Works Research Center (PWRC) product certification reports. The database comprises a total of 130 tensile tests performed on undamaged (reference) tests and 390 tensile tests performed on exhumed damaged geogrid specimens. A total of 78 installation damage factors were computed by the writers representing 26 different geogrid products from 12 different product lines in combination with three different aggregate types. The field tests were carried out using a standard PWRC protocol and the calculation of installation damage factors and spread in data was carried out in a consistent manner by the writers. The data are shown to be in good agreement with the results of tests carried out on similar products reported in other countries. The installation damage factors summarized in this study provide a useful benchmark for future field installation damage test results in Japan and worldwide. The statistical analysis of variability in installation damage test results is a prerequisite for future probabilistic analysis and design for the ultimate tensile rupture limit state in geogrid reinforced soil structures and for load and resistance factor design (LRFD) calibration of this limit state.