Load-Transfer Criteria for Numerical Analysis of Axially Loaded Piles in Sand. Part 1. Load-Transfer Criteria.

Abstract : Part I describes a study of load-transfer criteria for analysis of axially loaded piles in sand using the discrete springs soil model. Various analysis methods for axially loaded piles are presented, along with a literature review of pile behavior in sands focusing on the changes the soil undergoes during pile installation. Available criteria for spring representation of soil are presented and summarized. The criteria are compated with actual field data from pile load tests and are critically evaluated based on these comparisons. Because of the poor performance of the available criteria, new criteria are proposed. The new criteria use maximum side and tip resistance values presented by Castello (1980). Castello's values are modified by the author to reflect the field data from the Lower Mississippi Valley. Displacement functions for side and tip resistance are developed based on correlations with field data for pile load tests. The new criteria are evaluated against pile load test data. Use of the critieria is demonstrated in an outline of an analysis. The new criteria are used to develop a set of design curves for the practicing engineer. Part II of this report is published under a separate cover, and presents load capacity curves for select steel and concrete pile.