Method for calculating axial force and settlement of pile foundation in consolidating and reconsolidating ground

The neutral plane solution has been widely used to estimate downdrag settlements and drag loads mobilized in piles in consolidating soil profiles. However, some of the basic assumptions made by the neutral plane solution may cause the calculated results to significantly deviate from the actual values. A beam on nonlinear Winkler foundation (BNWF) solution, in which the shaft friction capacity is updated as consolidation progresses proportional to the effective stress, is proposed to analyze the axial force and settlement of piles during consolidation and post-earthquake reconsolidation. The proposed method fully considers the effect of consolidation process on the axial force and final settlement of piles. The axial force and downdrag settlement by the proposed BNWF solution is compared with the measured ones from centrifuge tests on piles in both consolidating and reconsolidating ground. The proposed method produces more accurate estimates of pile settlement than the traditional neutral plane solution.