Study on the Design Method of Different Thickness-Diameter Ratios for Composite Foundation with Rigid Long and Short Piles

Abstract

Composite foundation can be designed as long and short piles that lie on different bearing strata with high bearing capacities. Researches have shown that for foundation with sufficient stiffness, the ratio of the thickness of cushion to pile diameter (thickness-diameter ratio) plays an important role on the exertion of bearing capacities of pile and soil between piles. Traditional method just applies equal thickness-diameter ratio to design composite foundation with long and short piles, which hinders the exertion of bearing capacity of composite foundation. To overcome this defect, this paper studies the relations between thickness-diameter ratio and the exertions of bearing capacities of pile and soil between piles. The design method of thickness-diameter ratio for composite foundation with long and short piles is also proposed in this study.