The invention discloses a construction method for a cast-in-place
pile through
punching and base expanding and a base expanding device. The method includes the steps of 1)
punching which includes reserving the
pile position and pressing a protection drum into soil by utilizing
hydraulic pressure; 2) base expanding which includes connecting a
drill rod and the base expanding device and placing the
drill rod and the base expanding device into the protection drum; 3)
pile end construction which includes pouring a hard bulk material into a hole, utilizing a heavy punch to conduct tamping repeatedly till the material is compacted and pressing a conical pile head into the pile end through the heavy punch; 4) pile body construction which includes that a connection
pipe is connected with the
drill rod through threads, the connection
pipe is welded with a first rod piece, two ends of the first rod piece are connected with a second rod piece through bolts, the second rod piece is arranged in a guide groove through a bolt, the first rod piece is fixed on the second rod piece through a bolt, a baffle is arranged on the connection rod, the connection rod is connected with the bolts, and the connection rod is welded at the bottom of a
slag clearing drum. The construction method is easy to implement, simple to operate, convenient to construct, reliable in piling quality, low in construction cost, high in bearing capability, simple in structure and convenient to use. Functions of a conventional base expanding device can be achieved, and the problem that a conventional base expanding
drill bit can not effectively clear
slag at the bottom of the pile is solved.