Innovation and Practice of Static Pressure Pipe Pile Construction Technology for Diversion Hole Filling in a Certain Project in Zhuhai

For high-standard factory buildings in urban areas with hard rock strata such as disordered distribution of single rocks and large undundation of bearing stratum rock surfaces, and with tight construction periods, through multiple scheme comparisons, a combined process of pneumatic down-the-hole hammer drilling, gravel clay soil filling and static pressure pile driving was adopted, and the pneumatic down-the-hole hammer drilling soil filling and static pressure pipe pile construction method was proposed. Research shows that PHC500 pipe piles can be effectively embedded in strongly weathered rock layers by 1.65 m. The ultimate bearing capacity test of a single pile reaches 3800 kN, and settlement observations indicate that the maximum cumulative settlement of the building is only 10 mm. By breaking rocks through high-frequency impact, the average drilling speed of strongly weathered rock strata reaches 8 m/h~15 m/h, and there is no need to frequently replace the drill bit. The working efficiency is high and the comprehensive cost is significantly reduced. Dry soil filling operation causes no mud pollution. Static pressure pile driving can avoid the noise and vibration problems caused by hydraulic hammering, meeting the environmental protection requirements for urban construction.