Centrifuge Model Tests of Basal Reinforcement Effects on Geosynthetic-Reinforced Pile-Supported Embankment

As an effective and economical structure, geosynthetic-reinforced pile-supported (GRPS) embankment has been used in the construction of roadbed of railway and highway in soft soil area. Its key load transfer mechanism includes the soil arching effect of the embankment fill and the tensioned membrane effect of reinforcement in the mattress. Via these two effects, more embankment load is carried by piles, and the total settlement and differential settlement of the roadbed can be under control. Four centrifuge model tests were conducted to study the reinforcement effect of geosynthetic on embankment stability and pile efficacy. The following results are achieved: the surface settlement and differential settlement of embankment could be effectively reduced through appropriate setting of reinforced mattress; Basal reinforcement increased the pile efficacy and was affected by the number of reinforcement layers; The tensile force of geogrid below the embankment shoulder was larger than that near the road center because of the lateral restraint of basal reinforcement.