Performance of Flexible Pile Composite Foundation with Lateral Constraint

Flexible pile composite foundation can reduce the cost of foundation treatment, but its considerable settlement constrains its application. The solution proposed in this paper is a method of setting the pile with lateral constraint. Two comparative laboratory experiments were performed to analyse the lateral constraint pile’s influence on the composite foundation. The pile settlement and soil under the load were measured by monitoring the surface marks of the composite foundation. Soil and stresses in the composite foundation of piles were monitored through earth pressure cells placed on the foundation surface, the tips and bottoms of the piles and the PVC tubes, and the strain gauges on the pile shafts. The comparative experiments show that in the same experimental conditions, the settlement of the flexible pile composite foundation with lateral constraint is 25%-30% lower than that without lateral constraint, the stress on the pile tip is 18%-32% lower, and the stress in the pile shaft is also lower. These results indicate that the lateral constraint can effectively restrain the lateral deformation of the soft soil and improve the bearing capacity of the composite foundation.