Large scale field tests on geogrid-reinforced granular fill underlain by clay soil

This study aims at experimentally explaining the potential benefits of geogrid reinforced soil footings using large scale field tests. A total of 16 field tests were carried out to evaluate the effects of replacing natural clay soil with stiffer granular fill layer and single-multiple layers of geogrid reinforcement placed into granular fill below circular footings. The large scale field tests were performed using different size of the circular footing diameters which have 0.30, 0.45, 0.60 and 0.90 m. The results of testing program are presented in terms of subgrade modulus and bearing capacity. These values were calculated for each test at settlements of 10, 20 and 30 mm. Based on the test results, it is shown that the use of granular fill and geogrid for reinforced soil footings (RSF) have considerable effects on the subgrade modulus and bearing capacity. Finally, the field test results are compared to the analytical methods proposed by different researchers including the statistical correlations.