Deflection Behaviour of GFRP Bar Reinforced Concrete Passive Bored Pile in Deep Excavation Construction

This paper describes the investigation of a glass fibre reinforced polymer bar (GFRP bar) as a replacement for a traditional steel bar reinforcement in bored concrete piles with specific application to deep excavation construction. These two concrete passive piles were cast and experiments were conducted with reference to soil excavation. Normally, the point load which is applied to the pile head is provided by static lateral load test equipment for determining the pile behaviour; however, these two piles suffered from changed earth pressure during excavation. The amount and location of horizontal movement was monitored along the pile length by an inclinometer system which contained a PVC tube and a readout probe. The deflection behaviours of GFRP piles during the installation of one concrete and two steel supports were provided. It is concluded that, based on the difference between the total accumulated deflection of each pile, the GFRP bar reinforced concrete piles can resist the lateral loading and can provide an alternative to traditionally reinforced concrete piles used in shield construction.