Abstract: According to the similarity theory of model test, sand soil was used to simulate the soil layer in the field. The comparative studies of the laboratory model show that the axial capacity of the threaded steel pile is 1.34~1.92 times those of the identical diameter pile without shreds. When the thread spacing was densified from 100 mm to 50mm, the uplift capacity was 1.1 times of that of 100 mm spacing. The soil pressures, skin friction and the axial capacity of threaded pile with thread spacings of 100 mm and 50mm were comparatively studied and it was concluded that spacing of 50mm threaded pile is a better product. The empirical formula for the axial uplift capacity is was also recommended based on the test results.

Key words: shredded steel pile, uplift capacity, axial capacity, laboratory model tests