Pullout and bearing characteristics of grouted screw pile method

Screw pile provides large pullout resistance capacity due to the anchoring effect of the blade fixed at its lower end. Such pile transfers load to the bearing layer through the blade. In this research, a grouted screw pile method is developed. The newly developed grouted screw pile method improves the bearing capacity through cement column obtained by injecting compressed cement grout from non-return valves. Plate loading tests were conducted on the developed technique. Pullout test showed that cement columns generate higher skin friction than the conventional techniques. In addition, the bearing capacity was calculated from the shear resistance formula based on assumption of cone-shaped failure. The calculated results could explain well the tests results.