A Case History of Pile Freeze Effects in Dense Florida Sands

Increase in pile capacity from the freeze/setup effect after initial driving has been observed and studied by a number of researchers. This phenomenon not only occurs in clays but also in sands. On many occasions, the pile freeze effect was also observed in dense to very dense sands. This paper presents the Ernest Lyons Bridge project, in Stuart, Florida, as a case history to demonstrate pile freeze effects observed in dense sands. In this project 24-inch square prestressed concrete piles were driven over 25 feet into very dense sands. A comparison of estimated pile capacities at the end of initial driving (EOD) and the beginning of redrive (BOR) obtained by the Pile Driving Analyzer (PDA) with that predicted by the Program SPT-97 are discussed. Although it is well known that setup occurs primarily from side shear along the pile shaft, unless the static load test is performed, it is difficult to separate the side shear from the end bearing. Therefore, in this paper, the total pile capacity including side shear and end bearing were used to evaluate freeze effects. A conservative Setup Factor, A, which is the change in capacity normalized by the initial capacity per log cycle of time, of 0.2 was derived for the project site.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044107
  • Record Type: Publication
  • Report/Paper Numbers: 07-0730
  • Files: PRP, TRIS, TRB
  • Created Date: Feb 8 2007 5:18PM