Front edge expanded bulb having internal excavation method used high strength steel pile

摘要

PURPOSE: An excavation device for a front edge expansive internal excavation method using a high strength steel pile is provided to smoothly penetrate a steel pipe without the resistance of soil which is excavated by rotating and penetrating a steel pipe using an expansive bit. CONSTITUTION: An excavation device for a front edge expansive internal excavation method using a high strength steel pile comprises the following steps: operating an upper auger to excavate soil using an expansive bit head and rotate a steel pipe connected to a lower auger; gradually spreading an expansive bit while rotating and lifting an auger screw; vertically reciprocating the expansive bit several times and forming a preparatory expansive hole on the rock bed; and injecting grout through an inner pipe while vertically reciprocating the expansive bit and forming an expansive hole by stirring the grout.