Research on the Application of Static Drilling Root Planting Pile Technology in Urban Rail Transit

Conventional pile foundation technologies for urban rail transit are hindered by challenges such as difficult quality control, severe environmental pollution, and poor adaptability to complex strata. In response, this study systematically investigates static drill rooted pile technology to develop a green and efficient solution for complex urban rail scenarios. The research focuses on three key aspects: (1) Pile type improvement: A composite system integrating PRHC reinforced piles and PHDC bamboo-jointed piles is developed, incorporating pin-type mechanical joints to synergistically enhance uplift, bending, and horizontal resistance capacities; (2) Process optimization: A collaborative construction workflow is established, featuring dynamic adaptive drilling, graded pressure-controlled base expansion, differentiated grouting, and precise pile planting; (3) Monitoring upgrade: A dual-dimensional intelligent control platform focusing on safety and quality is implemented to monitor 12 critical parameters. Engineering case studies validate the proposed technology, showing that the optimized system increases single-pile compressive bearing capacity by 20%–30%, achieves an uplift safety factor of 1.79, reduces slurry discharge by over 70%, and attains a Class I pile quality rate exceeding 95%. This system effectively resolves construction challenges in complex strata, demonstrating significant advancements in bearing performance, environmental sustainability, and construction quality, thereby holding substantial value for broader engineering application.