Abstract:Taking the pile foundation project of the Dean market in Jiujiang area of Jiangxi Province as an example, this paper introduces the application and key technical measures of rotary drilled cast-in-place piles with air-lift reverse circulation hole cleaning and the vibration hammer for setting steel casing. The rotary drilling rig has a high efficiency in the construction of pile foundation, but control of settlements is difficult in the loose and collapsible stratums; therefore, it is the key to the success of the project to solve the problem with the settlements. Practice has proved that the combination of the vibrating hammer for setting casing to protect collapsible formation with the air lifting reverse circulation for cleaning can completely solve the problem of excessive settlements at the bottom of the hole.