Experimental Study on the Effect of Adding a Hoop Beneath the PHC Pile Endpoint

In the course of power driving, damage to the PHC pile head and body often occur because of the exorbitant blow count or blow energy, the compacting effect and vibration effect also have an evil influence to the surroundings. By adding a hoop beneath the PHC pile endpoint, the influence of frictional force of pile side can be reduced. Based on the comprehensive test pile in a power plant project, through the research to the total blow count, final injection depth, soil plugging height, vibration test and high-strain test, we show that adding a hoop beneath the PHC pile endpoint has better effect to keep the pile integrity and reduce the vibration effect, the final ultimate bearing capacity of single pile is not be affected, the effect to compacting effect is also weak. This research results have references to pile driving in the construction of the power plant and similar porjects.