Installation load and working capacity of jacked piles: some experiences in China

Abstract

The working capacity of jacked piles may be self-proved by the load experienced during installation, since the press-in penetration and the static loading test have similar physical background. The ratio of pile’s ultimate capacity to the final jacking load, defined as the pressure ratio in this study, is an interesting but tricking issue in jack piling design and construction. Focus is paid on how the pressure ratio varies with pile’s slenderness ratio and the condition of surrounding and end-bearing soils. With a primary concern on the concrete piles widely used in China, several empirical correlations used in practice are summarized and examined. A new database, with test piles collected from different parts of China, is then presented in an attempt to seek for an effective way to consider the effect of soil condition. A simple sorting method in terms of fine and coarse soils has the potential to properly consider the different behaviors arising from the pile-equalization stage.