Plate load tests on geogrid-reinforced expanded shale lightweight aggregate

recent years, use of lightweight aggregates in geotechnical applications has increased. An experimental study was therefore conducted on geogrid-reinforccd lightweight aggregate beds to determine their subgrade modulus. A total of 25 plate load tests were performed in a laboratory test pit measuring 2.2 x 3.2 x 1.6 m deep using a 305 turn diameter rigid steel plate. Parameters varied in the study included: soil density (compact and very loose), width of soil reinforcement, location of the top geogrid layer, number of geogrid layers and the tensile strength of geogrid. The results of the testing program are presented in terms of subgrade modulus rather than bearing capacity ratio as traditionally presented in the literature. Subgrade modulus values were calculated for each test at settlements of 6, 12.5 and 25 mm. The results are compared with the data reported in the literature on geogrid-reinforced sands and ceramic beads. (C) 2002 Elsevier Science Ltd. All rights reserved.