Experiment on Improving Bearing Capacity of Pile Foundation in Loess Area by Postgrouting

Postgrouting technology is an inevitable trend in the development of bored piles in the loess area. To study the behavior of end resistance, lateral friction, and bearing capacity of postgrouting pile and conventional pile, the mechanism of improving the bearing capacity of postgrouting at the end of pile is analyzed by the static load failure test of pile foundation, combined with the principle of grout‐soil interaction and Bingham fluid model. The results show that the grout‐soil interaction enhances the strength of pile end soil and promotes the exertion of end resistance; the relative displacement of pile‐soil decreases, while the lateral friction increases with the change of the interface property of pile‐soil; simultaneously, the climb height of grouting is approximately the theoretical analysis value. In addition, postgrouting can obviously improve the bearing characteristics of the pile so that the settlement of the pile foundation is slowed down and the bearing capacity is increased.