Application of Bored Cast-in-place Pile Construction Technology in a Project in Guangzhou

In order to cope with the quality and efficiency challenges of bored cast-in-place pile construction under complex geological conditions, this paper takes the project of karst strong development area in Shafeng Village, Jinshazhou, Guangzhou as an example to carry out construction process optimization research. The research abandons the traditional "clay + rubble backfilling" method of passively treating karst caves, innovatively adopts "controlled pressure grouting consolidation method" as the core technical countermeasure, and systematically constructs a quality control system covering "equipment access-personnel training-geological accurate survey-whole process fine management and control-multi-method cross detection". The practical results show that the optimized process significantly shortens the treatment time of single pile without filling karst cave from the traditional 36-48 hours to less than 10 hours, and the construction efficiency is improved by more than 80 %. The tested pile is determined to be a class I pile, and the concrete wave velocity of the pile body is in the normal range, indicating that the pile body is complete and the quality is uniform. The results of static load test further confirm that the bearing capacity of pile foundation is good, the settlement of pile top is small (the maximum settlement is 9.62 mm) and the rebound rate is high (37.1 %). This study confirms that the proposed comprehensive technical route can effectively solve the problem of hole formation under complex geology, significantly improve the quality of pile formation and construction efficiency, and provide a replicable practical scheme for similar projects.