Innovative design of pipe piles combined both the effect of pile foundation and composite foundation for soft soil treatment

Abstract

The soft soil treatment is one of the hot issues needed to be solved in many constructions including tunnels, freeways, etc. In this paper, a prefabricated pipe pile with side openings and wrapped geotextile is first proposed aiming to realize both the effect of pile foundation and composite foundation for soft soil treatment, which could be capable of draining and increasing frictional resistance. It combines fast drainage consolidation and high bearing capacity, which could be used under different engineering conditions with different designs. Small holes on pipe pile provide the drainage channel for vacuum to accelerate the consolidation and reduce the squeezing effect. The geotextile wrapped outside reduces the friction in pile-driven process and has the anti-filtering effect to ensure the long-term stability of the drainage channel. After the consolidation, the drainage pipe pile is grouted to form a composite foundation with high bearing capacity, which has good time, economy and environmental benefits. The drainage pipe pile can be developed to some special designs for dam filling and reclamation of islands. The proposed innovative designs of pipe pile could satisfy the demand of high bearing capacity and quick consolidation on soft soil, which combine both the effect of pile foundation and composite foundation.