DISCHARGING CHARACTERISTICS BY SCREW AUGER OF GRAVEL DRAIN PILE

Abstract

The gravel drain pile is widely used in the antiseismic reinforcement of an existing construction as a liquefaction prevention method that works by dissipating the excess pore water pressure. This method discharges soil by the screw around the casing pipe in order to decrease the displacement. Since the discharged soil volume influences the displacement, it is important to predict and control the discharged soil volume generated from the penetration of the casing pipe.
In this study, the calculation equation for soil discharging capability based on such factors as screw specification, penetration speed, rotational speed, and ground characteristics is proposed. Comparison between the calculation results and the actual measurement of the discharged soil confirmed that the prediction equation is capable of representing the actual measurement. Enhancement of the calculation equation improves rational work management at the worksite.