Numerical Procedure for Predicting Pile Capacity—Setup/Freeze

Abstract

In geotechnical engineering practice, the increase over time of pile capacity after installation is sometimes referred to as pile setup or freeze. Pile setup, which is often associated with piles driven into saturated clays and silts, is mainly attributed to soil consolidation around the pile. Field observations have shown that pile setup is significant and continues to develop for a long time after pile installation. Pile foundations are usually expensive. Therefore, taking a small percentage of pile setup into consideration will result in cost reduction and savings in piling projects. This paper presents a general numerical procedure to predict pile setup by simulating the behavior of the pile during its different life stages: installation, subsequent consolidation, and loading. The Hierarchical Single Surface modeling approach, the strain path method, and the nonlinear finite element analysis of porous media were used in the analyses. The procedure was verified by successfully predicting the field behavior of pile segment models installed into soft marine clay. Numerical experiments were also conducted to demonstrate the applicability of the numerical procedure to full-scale driven piles. Piles with diameters of 0.3 m and 0.5 m and a length of 10 m were considered in the analyses.