外振内击扩底灌注桩是一种新型小口径扩底灌注桩。它利用振动锤或振动锤和内击锤的共同作用，将桩管沉到设计标高，然后灌人干硬性混凝土，用内击锤将干硬性混凝土夯出管外，制成扩大头，再吊放钢筋笼和灌注桩身混凝土，最后拔极管而成。1施工特点（l）振拔灌注桩具有设备简单 External vibration internal blasting grouting pile is a new small-diameter enlarged bottom pouring pile. It uses the vibrating hammer or vibrating hammer and internal hammer to work together to sink the pile pipe to the design elevation, then fill dry concrete, and use the internal hammer to pull dry hard concrete out of the pipe to make it an enlarged head and then hang it. Put reinforcement cages and concrete into the pile, and then pull the pole tube. 1 Construction features (l) Vibration-sweeping cast-in-place piles have simple equipment