Abstract
In this study, evaluation of in-situ compressive stiffness of backfilling ground reinforced with fiber was discussed. A model ground made at the test field by backfilling with Liquefied Stabilized Soil (LSS) reinforced with fiber amount of 0 and 20 kg/m3 was subjected to portable Falling Weight Deflectometer (FWD) tests at curing time of 28, 56 and 84 days, respectively. The stiffness was estimated by Young’s modulus EP.FWD calculated from KP.FWD-value as the coefficient of subgrade reaction. In parallel, in order to obtain the tangent Young’s modulus Etan in deviator stress and axial strain (q -ea) curve, a series of Consolidated–Undrained triaxial compression tests under the conditions at constant strain rate, constant deviator stress (partial creep test), and changed strain rate during monotonic loading have been carried out for specimens prepared by trimming LSS retrieved from the model ground by block sampling. Based on the test results, the relationship between the EP.FWD and Etan was discussed. It is considered that the KP.FWD-value is able to estimate the stiffness of backfilling ground by LSS reinforced with fiber.
