Details:

Creators:
Coe, Joseph T. ; Nyquist, Jonathan E. ; Kermani, Behnoud ; Sybrandy, Lorraine
Coe, Joseph T. ; Nyquist, Jonathan E. ; Kermani, Behnoud ; Sybrandy, Lorraine Less -
Corporate Creators:
Temple University
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Bridge Foundations Evaluation And Assessment Field Tests Laboratory Tests Nondestructive Tests Scour Ultrasonics
Publication/ Report Number:
FHWA-PA-2013-003-TEM 002
Resource Type:
Tech Report
Geographical Coverage:
Pennsylvania
Corporate Publisher:
Pennsylvania. Dept. of Transportation. Bureau of Planning and Research
Abstract:
Unknown bridge foundations present a unique challenge to Departments of Transportation (DOT) across the country since

foundation characteristics are a necessary input to assess scour vulnerability and to develop appropriate scour countermeasures.

A number of non-destructive testing techniques have evolved over time to address this challenge and evaluate unknown

foundation type and geometry. The most comprehensive study of NDT methods for unknown foundations was performed as part of

National Cooperative Highway Research Program (NCHRP) 21-05 in 2001. Since NCHRP 21-05 other case studies have

expanded the literature and further advancements in computer software and hardware have improved NDT capabilities and

reliability for unknown foundation evaluation. In particular, P-wave reflection imaging has the potential to provide higher resolution

data and significantly more detail regarding the subsurface in both the laboratory and the field.

An ultrasonic P-wave reflection imaging system was investigated in this study as a viable NDT method to assess unknown

foundations. The P-wave system was originally developed to image large scale soil models in the laboratory and to image the

profile of vertically embedded structural elements such as foundations. The P-wave system was utilized in a field testing program

to image the vertical profile of foundations at two bridge sites in southeastern Pennsylvania. Site selection, characteristics of the

foundations tested, and the site soil conditions are summarized. The final foundation depths were unknown to the research team

at the sites, which resulted in a true blind study and simulated the unknown foundation problem. The ultrasound probe was

lowered in a PVC-cased borehole alongside the foundation to generate and record P-wave signals. The resulting data was plotted

to construct an image and predict foundation characteristics. Multiple NDT techniques including Parallel Seismic, Borehole

Magnetometer, and Borehole Radar were also performed at the sites in conjunction with the P-wave testing. The resulting data

and interpretation of foundation characteristics are compared between all methods.


Format:
PDF
Funding:
510801, TEM 002
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:2509767fc6b841ec7c274988c5ea0bb3853e8fe8e503dee663b9542462f315d1
Download URL:
https://rosap.ntl.bts.gov/view/dot/26680/dot_26680_DS1.pdf
File Type:

Supporting Files

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