Bearing capacity behavior of roll forming filling screw pile (screw pile for short) is investigated through numerical calculation and static load test. The influence of pile-type parameters

such as width of thread tooth and thread pitch

on the ultimate bearing capacity of crew pile is studied; furthermore

the bearing capacity behavior of screw pile and that of pile with the same diameter are compared and analyzed through static load test. The results show that the ultimate bearing capacity of screw pile is a bit higher than that of pile with the same outside diameter; width of thread tooth has a distinct effect on ultimate bearing capacity which increases with the increment of width of thread tooth. When the screw pile is tested under light load

the resistance on pile side is distributed along screw pile

and tip resistance is small

but the resistance rises considerably with load increasing. Besides

the design formula of bearing capacity of screw pile is proposed.