Field Monitoring Study on Load‐Bearing Performance of Adjustable Pile‐Supported Wind Turbine Foundation in Open‐Pit Mine Dump Sites

To investigate the operational stress response and load‐transfer mechanisms of adjustable pile‐supported wind turbine foundation in open‐pit mine dump environments, a site‐specific monitoring scheme was developed for open‐pit mine dump environments, incorporating structural features of the foundation system. Comprehensive field data including pile reinforcement stress, pile cap concrete strain, base soil pressure, and foundation floor reinforcement stress were systematically acquired to analyze load‐transfer laws and stress evolution. Key findings reveal that initial load dissipation occurs through combined action of cast‐in‐place piles and foundation soil. However, progressive cyclic loading induces differential stiffness responses, triggering significant settlement in interpile soil zones and subsequent load redistribution toward piles, evidenced by an increasing pile–soil load‐sharing ratio. This is quantitatively evidenced by an increasing pile–soil load‐sharing ratio, exemplified by a rise in the side resistance contribution from 81.3% to 84.3% at a monitored pile located on the windward side. The piles sustain persistent compressive stresses with depth‐dependent axial force attenuation; significant negative friction develops near pile tops due to differential settlement. Pile caps exhibit negative correlation with base soil pressures, while cumulative pressure‐strain responses reflect load distribution effects. Although the stress concentration in the outer ring reinforcement of the foundation slab is higher than that in the inner ring, the overall foundation slab maintains a stable state. Measured data on foundation settlement and tilt ratio are within the allowable ranges specified in the Chinese industry standard for onshore wind turbine foundation design (NB/T 10311‐2019), confirming the wind turbine operates under safe conditions.