Concrete post foundation hole prodn. - involves lowering pipe into ground using vibrator and core is removed using differential air pressure

摘要

The process is for the positioning of concrete posts or similar construction elements, in the ground. A hole is dug in the ground, corresponding to the cross section of the post. A pipe (16), open at the bottom, and having the desired cross section, is pressed into the ground by a vibrator, placed onto its top end. A pressure differential, relative to atmospheric pressure, is produced in an end section of the pipe, to keep the soil within the pipe. The pipe is then retracted while the pressure is maintained within it. Compressed air is introduced at the lower end of the pipe, and the supply is maintained, while the pipe is withdrawn. The top pipe end is sealed air-tight after insertion.