Abstract: Rock socketed piles have the advantages of high single pile axial capacity, less settlement, and matured construction procedures, making them widely applicable to building foundations with high axial capacity requirements. A high-rise residential project adopted the rock socketed pile foundation. Due to geological conditions and the construction techniques on the site, there were multiple occurrences of slurry leakage and borehole caving during the pile installations, which seriously affected the quality of the pile foundation and led to insufficient axial capacity of some mono-pile foundations. By comparing the detailed subsurface information and pile installation data, analyzing the static load test and low strain integration test data of these piles, and verifying the concrete coring method, the article explores and analyzes the potential reasons for the quality hazards of these rock socketed piles, and provides detailed solutions. After the problematic piles are mitigated, the single pile axial capacity could meet the design requirements. It is confirmed that the mitigation plan is feasible.

Key words: Rock Socketed Piles, Jet Grouting, Karst