Predicted Behavior of Axially Loaded Piles in Sand

Abstract

Field tests on 22 steel pipe piles either embedded or bearing in sands are reviewed to determine depth and displacement dependent design parameters. These parameters are used to forecast the behavior of 9 additional piles. A procedure to predict ultimate and allowable loads and corresponding displacements is presented.

A Three-Dimensional Nonlinear Study of Piles Leading to the Development of a Simplified Model

“…An apparent advantage of this class of methods is that they can incorporate inelastic soil behavior by using nonlinear curves for its representation without complicating the analysis; however, early t-z or p-y curves were simply backfigured from the results of a limited number of experiments on certain soil types, and thus their application was practically limited to soils similar to the soil at the site of the field test associated with their derivation. Such experimental t-z curves have been developed for sand (Sulaiman and Coyle 1971), soft clay Reese 1966, Holmquist andMatlock 1976), and stiff clay (O'Neill et al 1982); similarly, experimental p-y curves have been presented for sand (Reese et al 1974), soft clay (Matlock 1970, and stiff clay (Reese and Welch 1975). More recently, attempts have been made to derive theoretical t-z curves (Kraft Jr. et al 1981), based on modeling the soil as concentric cylinders surrounding the pile and undergoing shear deformation, and to unify the derivation of p-y curves for soft or stiff clays (Gazioglou and O'Neill 1983); in addition, Georgiadis (1983) proposed a method for developing p-y curves for layered soils with properties significantly varying between layers, q-z curves for the tip resistance are derived from the solution of the problem of a rigid punch inside an elastic halfspace (Kraft Jr. et al 1981).…”