This invention is applied when steel pipe piling work is processing. The methodology is followed by the steps below: 1) clean the substance 2) put the pile base expending equipment in the steel pipe and drive into the designed enlarging point 3) use hammer grab to clear the bored hole 4) pour concrete in

This methodology not only can increase bearing area and strength of the structure but also can increase the convenience of subsequent rebuilds. Besides, the cost and working hours of the expansion project can also be saved.