What is Pile Failure for Large Diameter Open-End Piles?-PPT Presentation

PPT Presentation

Pdf Summary

The FHWA large-diameter open-ended pile (LDOEP) research project compiled 150 load tests, updated the deep foundation load-test database, assessed existing static design methods, and developed LDOEP-specific resistance factors. A central challenge was determining how to interpret load–displacement test data and define pile failure.<br /><br />The study found that load–displacement behavior varies with pile dimensions, soil conditions, and whether the pile is plugged or unplugged. Responses may show plunging or strain hardening, and long piles can undergo substantial elastic compression. Consequently, different failure criteria can produce significantly different displacement and resistance estimates.<br /><br />After reviewing available criteria and conducting statistical analyses, the researchers selected three methods for consideration: Davisson, Modified Davisson, and displacement at 5% of pile diameter. The presentation recommends evaluating all three in light of the measured force–displacement response and the performance requirements of the supported structure, rather than relying on a single universal definition of failure.

Keywords

large-diameter open-ended pile

FHWA

load test database

deep foundation

load-displacement behavior

pile failure criteria

Davisson method

Modified Davisson

5 percent pile diameter

resistance factors