Seismic response of hollow fibre-reinforced polymer (FRP) piles in soft clay using shaking table tests

This study aimed at investigating the seismic performance of hollow fibre-reinforced polymer (FRP) piles compared to traditional piles in soft clay deposits using shaking table tests. A laminar shear box with dimensions of 1.0 × 1.0 × 1.0 m was used to contain the soil medium and allow it to respond similarly to the free field. Two types of composite group piles (2 × 2) made of carbon fibre-reinforced polymer and glass fibre-reinforced polymer, along with aluminium piles, were manufactured and embedded as end-bearing piles within the soil. Several monitoring instruments were used to observe the soil–pile response under variety of ground motions adopted from the 2010 Val-des-Bois Earthquake in Canada and the 1995 Kobe Earthquake. Seismic response of the foundation was strongly dependent on the stiffness provided by the soil, which was a function of the degree of softening and intensity of shaking. The foundation motion of model piles was higher than those of the free field mainly because of strong kinematic soil–pile interaction. Among the model piles, FRP piles revealed lower foundation motion due to their lower flexural stiffness compared to aluminium piles. This could make FRP piles a remarkably viable option compared to conventional piles under seismic loading.