Improved assessment of mass concrete dams using acoustic travel time tomography. Part II — application

Abstract

The aging of key elements of our civil infrastructure, including dams, is presenting new challenges for the development of methodology that will adequately predict remaining safe life, and identify those structures where remedial action is required. To meet this need, a new approach for non-destructive testing of large concrete dams has been developed. It combines aspects of ultrasonic non-destructive testing and seismic surveying in a new methodology ‘Acoustic Travel Time Tomography’ (ATTT). This is the second part of an investigation on improved assessment of mass concrete dams using ATTT. A companion paper [Bond LJ, Kepler WF, Frangopol, DM. Improved assessment of mass concrete dams using acoustic travel time tomography. Part I — Theory. Constr Build Mater 2000 Vol. 14, No. 3, pp. 133–146] focused on the background of the physics of ATTT. ATTT was tested in the laboratory, modified for large-scale testing, then evaluated for reliability. This study reports the application of the methodology, instrumentation, and data analysis techniques developed during the study. The research demonstrates that ATTT can locate and characterize cracks, voids and other anomalies deep within a mass concrete dam. The results at each stage of the study have shown that ATTT is a potentially highly accurate testing procedure, and that it is uniquely suited to the evaluation of large concrete dams.