Centrifuge model tests on the behavior of strip footing on geotextile-reinforced slopes

Abstract

This paper examines the stability of geotextile-reinforced slopes when subjected to a vertical load applied to a strip footing positioned close to the slope crest. Vertical spacing between geotextile reinforcement was varied while maintaining a constant slope angle, load position, soil density and geotextile type. Small-scale physical tests were conducted using a large beam centrifuge to simulate field prototype conditions. After the model was accelerated to 40 g, a load was applied to the strip footing until slope failure occurred. Digital image analysis was performed, using photographs taken in-flight, to obtain slope displacements and strain distribution along the reinforcement layers at different loading pressures during the test and at failure. Stability analysis was also conducted and compared with centrifuge model test results. The vertical spacing between reinforcement layers has a significant impact on the stability of a reinforced slope when subjected to a vertical load. Less vertical distance between reinforcement layers allows the slope to tolerate much greater loads than layers spaced further apart. Distributions of peak strains in reinforcement layers due to the strip footing placed on the surface of the reinforced slope were found to extend up to mid-height of the slope and thereafter they were found to be negligible. Stability analysis of the centrifuge models was found to be consistent with the observed performance of geotextile-reinforced slopes subjected to loading applied to a strip footing near the crest.