An ultrasonic P-wave borehole system was developed as a nondestructive testing (NDT) technique to evaluate the
length of embedded bridge foundation elements. The system is designed to be lowered within a PVC-cased
borehole. Ultrasonic P-waves are transmitted into the soil and the corresponding reflection signals are plotted to
generate an image of the foundation. This paper summarizes the suite of laboratory tests that were performed as part
of the development of this system. A large soil model was constructed in the laboratory and multiple objects
composed of steel, timber, concrete, and various plastics were embedded throughout different cross sections of the
model. The effects of borehole construction were mimicked by varying the thickness of the PVC and the presence of
a grout layer. The results show that under ideal conditions the system is capable of recording reflection signals from
objects embedded in 0.9 m of soil. Moreover, the system can detect object edges to within approximately 5% of
their true locations.
1. Arneson, L.A., Zevenbergen, L.W., Lagasse, P.F., and Clopper, P.E. (2012). “Evaluating Scour at Bridges,"
Hydraulic Engineering Circular No. 18, Fifth Edition, Publication No. FHWA-HIF-12-003, Federal Highway
Administration, Washington, D.C.
2. Briaud, J., Medina-Cetina, Z., Hurlebaus, S., Everett, T., Tucker, S., Yousefpour, N., and Arjwech, R. (2012)
“Unknown Foundation Determination for Scour.” Report No. FHWA/TX-12/0-6604-1, Texas Department of
Transportation, Austin, TX.
3. Coe, J. T. and Brandenberg, S. J. (2010). “P-wave Reflection Imaging of Submerged Soil Models Using
Ultrasound.” Journal of Geotechnical & Geoenviromental Engineering, Vol. 136, No. 10, 1358-1367.
4. Coe, J.T. and Brandenberg, S.J. (2012). “Cone Penetration Test–Based Ultrasonic Probe for P-Wave Reflection
Imaging of Embedded Objects.” Journal of Bridge Engineering, Vol. 17, No. 6, 940-950.
5. Descour, J.M., and Kabir, J.J. (2010) “Imaging Piles in Bridge Foundations Using Tomography and Horizontal
Seismic Reflector Tracing.” Proceedings Geo-Florida 2010, West Palm Beach, FL.
6. Hertlein, B.H., and Walton, W.H. (2007). “Project Experience in Assessment and Reuse of Old Foundations.”
Proceedings of Geo-Denver 2007, Denver, CO.
7. Jalinoos, F., Gibson, A., Diehl, J., Hadfield, P. and Gordon, G. (2006). “Determination of Unknown Length of
Sheet Piles Using Three Geophysical Logging Methods” 2006 Highway Geophysics NDE Conference, St.
8. Jo, C.H., Cha, Y.H., and Choi, J.H. (2003). “A Borehole Magnetic Logging Tool for Estimating Unknown
Foundation Depths.” 2003 Highway Geophysics NDE Conference, Orlando, FL.
9. McLemore, S., Zendegui, S., Whiteside, J., Sheppard, M., Gosselin, M., Demir, H., Passe, P., and Hayden, M.
(2010). “Unknown Foundation Bridges Pilot Study.” Federal Highway Administration & Florida Department of
10. Olson, L.D., and Aouad, M.F. (2001). “Unknown Subsurface Bridge Foundation Testing, NCHRP Project 21-
05(2) Final Report.” National Cooperative Highway Research Program (NCHRP), Transportation Research
Board, Washington, D.C.
11. Olson, L., Jalinoos, F., and Aouad, M.F. (1998). “Determination of Unknown Subsurface Bridge Foundations:
A Summary of the NCHRP 21-5 Interim Report.” Geotechnical Engineering Notebook, Geotechnical Guideline
No. 16, Federal Highway Administration, Washington, D.C.
12. Robinson, B., and Webster, S. (2008). “Successful Testing Methods for Unknown Bridge Foundations.”
Proceedings of The Fifth Highway Geophysics NDE Conference, Charlotte, NC.
13. Yu, X., Fang, J., Zhang, B., Adams, J. and Lin, G. (2007). “Unknown Foundation Testing: A Case Comparison
of Different Geophysical Methods.” FMGM 2007: Seventh International Symposium on Field Measurements in
Geomechanics, Boston, MA.