Repeated loading of soilbag-reinforced road subgrade

Abstract

Soilbags are three-dimensional soil-confining units used in road foundations. This paper uses vertical repeated loading tests to investigate the performance of soilbags as reinforcement in road subgrades as well as the influence of such factors as the frequency and amplitude of loading, the number of reinforcement layers, and the buried depth of the soilbag reinforcement. The results show that soilbags as reinforcement are effective at reducing permanent and resilient deformations of the road subgrade as well as vibrations caused by traffic loads. The soilbags as reinforcement perform better when the number of soilbag-reinforced layers is increased. More than two layers of soilbags are needed to reinforce the road subgrade to make efficient use of the effect of interlayer insertion between soilbags. Furthermore, a thin surface soil cover is desirable to spread the applied pressure more effectively over the soilbags and level the subgrade.