Settlement Prediction for Cast-in-Place Tubular Piles with Large Diameters Based on the Load Transfer Approach

Large-diameter cast-in-place tubular piles offer high efficiency and adaptability for various engineering applications. Despite their widespread use, the bearing behavior of these piles remains complex due to the interactions with the internal soil core, and the related theoretical framework is not yet fully developed. In this study, a simplified load transfer model is proposed based on the pile–soil interaction mechanism of large-diameter tubular piles. Comprehensive load transfer models for the skin friction and end resistance of both the pile body and the soil core are established, supported by a detailed theoretical analysis. A novel three-criteria approach is introduced for the first time to enhance settlement predictions for large-diameter tubular piles by considering the displacement coordination mechanism of the internal soil core, addressing the limitations of traditional two-criteria methods. The proposed methods are validated through two engineering case studies, demonstrating their effectiveness and confirming their rationality and applicability in practical scenarios.