MODEL TESTS OF INSTALLATION AND BEARING CAPACITY OF SCREWED PILES

Abstract

Installation and vertical loading tests of screwed steel pipe pile, which has helical wing on the pile edge, were executed in uniformly graded sand in a calibration chamber. The experimental factors are the relative density D_r(72, 94%), the pile diameter d_0(48.6, 76.3, 101.6mm) and the surcharge pressure σ_0(50, 100, 150kPa). It was proved that the residual stresses of screwed pile installed in the dense sand amounted to high ratio, and the load deflection curves of the pile top due to vertical load were different from those of the other piles such as jacked pile or bored pile. We have discussed the effect of the residual stresses upon the bearing capacity of the screwed pile.