DFI Magazine September/October 2020 - 115

FEATURE

ARTICLE

CSL testing on a drilled shaft

Improving Crosshole Sonic Logging Interpretations
Late in 2019, Deep Foundations Institute
(DFI) published "Terminology and Evaluation Criteria of Crosshole Sonic Logging
(CSL) as Applied to Deep Foundations." The
white paper, which is covered in this article,
reviews the state of the practice after 20 years
of CSL experience, proposes improved CSL
rating criteria, makes recommendations for
additional assessment and attempts to
educate the industry on the proper
interpretation of CSL results.
The impetus for the document
stemmed from a panel discussion at
SuperPile in 2016 about the terminology
used to describe CSL results. Misery loves
company, and when testing consultants
traded war stories at deep foundation
conferences, it became apparent that
testers (who often had no other role in the
projects) were being asked, "So, do these
CSL results mean we have to reject the
foundation?" Co-author Sellountou

AUTHORS

approached Bernie Hertlein, FACE, of GEI
Consultants, about creating a document to
improve current CSL practices and clarify
problematic terminology that lead to
panicked discussions and unnecessary
rejection of foundations. It was envisioned
that a document could be developed to
foster greater consistency in CSL
interpretation by the industry, thereby
reducing the difficulties encountered on a
project-by-project basis. Essentially, the
goal was creating a document that helped
the industry while removing the burden
and unwarranted risks from individuals.
With Hertlein's support, Sellountou
approached DFI's Testing and Evaluation,
Codes and Standards, and Drilled Shaft
committees to gauge interest and recruit
authors. Ultimately, a task force was formed
within the Testing and Evaluation
Committee with Sellountou as chair. In
addition to Hertlein, Joram Amir, Ph.D.,

C.E., D.GE, (Piletest), Les Chernauskas,
P.E., (Geosciences Testing and Research),
Peter Kandaris, P.E., (DiGioia, Gray &
Associates), Tim Kovacs, P.E., (DBM
Contractors), Garland Likins, P.E., (GRL
Engineers), and co-author Greg Canivan,
P.E., (S&ME), joined the task force to help
author the white paper. Initially, Sellountou
created a document based on literature
review and submitted it to the task force.
Then for about 3 years, a majority of the
authors met twice monthly for 90 minutes
via conference call to revise and edit the text
based on their and outside expert
comments. By October 2018, the authors
felt they had a solid enough document to
have a panel discussion at DFI's 43rd Annual
Conference in Anaheim, California.
Subsequent to additional review and comment by industry members, DFI announced
the white paper's free availability for the
industry in October 2019.

Greg Canivan, P.E., S&ME, and Anna Sellountou, Ph.D., P.E., Pile Dynamics

DEEP FOUNDATIONS * SEPT/OCT 2020 * 115
DFI Magazine September/October 2020

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