Abstract: To improve the quality of mixing piles and further improve the quality of engineering,  the factors affecting the quality of cement mixing piles are analyzed, the causes for quality defects of cement mixing piles are studied, and corresponding solutions are proposed. The influence of sinking and lifting speed, drilling speed, blade width, blade angle, blade number, and blade combination mode of drill rod on the pile formation effect is analyzed, and a mathematical model is established. It is concluded that when the number and the effective mixing width of blade are constant, the greater the drilling speed  of the drill rod, the greater the allowable sinking and lifting speed; while the blade spacing does not affect the quality of the mixing pile.

Key words: cement mixing pile, construction parameters, drill rod sinking and lifting speed, rotation speed, distance between blades, mathematical model