Title:
The Reliability of Sonic Testing of Drilled Shafts
Author(s):
Mahmod A. Samman, and Michael W. O'neill
Publication:
Concrete International
Volume:
19
Issue:
1
Appears on pages(s):
49-54
Keywords:
inspection, nondestructive evaluation; sonic tests, stress wave;
DOI:
Date:
1/1/1997
Abstract:
The accuracy of low-strain stress wave testing (also known as sonic echo or seismic testing) of drilled shafts is assessed using a combination of theoretical and experimental data. The paper suggests that in most soils, the technique is capable of estimating the length of the shaft or the distance from the top of the shaft to the first whole section discontinuity if one exists with a precision of about plus/minus 15 percent. However, the technique is not capable of detecting or characterizing simulated defects with any useful accuracy. Consequently, the paper concludes that the results of sonic echo tests should not be used exclusively as either a screening or an acceptance criterion for drilled shafts.