Driving and casting procedure for bulbous foot piles - uses concrete rammer inside pile tube with projection above tube being equal to volume of concrete cast

摘要

The tube is driven into the foundation bearing ground to the required depth and sufficient concrete is poured into the tube to make a bulbous foot. An internal rammer is then inserted to rest on the concrete, its projection above the tube being equal to the volume of concrete cast. The tube is then partially withdrawn so that top of rammer and punch coincide. Both rammer and tube are now driven down forcing the concrete to take its bulbous form, the rammer and tube are then withdrawn simultaneously, reinforcement is inserted and the remainder of the pile is cast.