Geosynthetic-reinforced pile-supported embankment: settlement in different pile conditions

Three centrifuge model tests were conducted on geosynthetic-reinforced pile-supported (GRPS) embankments with side slopes to investigate the influence of pile end-bearing conditions and pile modulus on their performance. This study found that when end-bearing piles were used, differential settlement occurred at the base of the embankment and the majority of the embankment load was transferred to the piles. Floating piles, however, behaved as rigid inclusions and formed a composite foundation with their surrounding soil, which shared the total load under an approximately equal-strain condition. The use of end-bearing piles with low modulus increased the total settlement of the piles and the foundation soil at the base of the embankment and promoted lateral movement of the side slopes. Two theoretical methods were adopted with some modifications to calculate pile head settlement compared with the measured data. When the end-bearing piles were used to support the geosynthetic-reinforced embankment, the modified Vesic method considering negative skin friction along pile shafts was used to calculate the pile head settlement close to the measured one. When floating piles were used to support the geosynthetic-reinforced embankment, the modified equivalent footing method was used to calculate the settlement, matching reasonably well with the measured one.