The invention discloses construction
pile engineering and construction method, especially bottom expanding and
pile forming method for sinking-
pipe bottom expanded piles, comprising following steps: pressing the first segment of sinking tube into soil, connecting the second segment of tube with the thread on the top of the first segment of tube, pressing the sinking tube to hard soil of designed elevation; taking out the
metal pile head, putting into emulsible oil or AN-TNT explosive through the sinking tube mouth, and removing the articles blocking the sinking tube mouth after explosion is completed; taking out the broken soil by using an air soil suction device; throwing away dispersed articles from the sinking tube mouth, digging soil to expand the bottom; taking out soil for the third time; disposing the
steel bar into the base cavity and hammering same into hard soil, disposing the concrete into a long
barrel, disposing the long
barrel into the bottom of the sinking tube, sinking the prefab concrete pile body and anchoring same with the
cement paste base which is poured on site is anchored integrally by inserted steel bars at the bottom of the pile body; pulling out the first segment of sinking tube and the second segment of sinking tube, pouring
cement paste into the gap. Thereby, the pile is constructed. According to the invention, the expanded bottom has a regular
geometric figure, soil is taken out cleanly, no granule soil is left, and efficiency thereof is high.