Automated, Rapid, Comprehensive Non-Destructive Tunnel Testing

Automated seismic/sonic wave velocity, frequency and reflection measurements and radar profiling<br>measurements are obtained to provide a rapid, comprehensive and efficient non-destructive<br>evaluation of tunnel liner conditions. The automated seismic/sonic system acquires overlapping<br>(continuous data) at 6,18, and 30 inch intervals at a rate of 500 to 2,000 feet per hour. Radar profiling<br>data are acquired simultaneously to provide a complete suite of non-destructive data to evaluate the<br>following critical tunnel parameters:<br>. strength of the tunnel liner;<br>. identification and mapping of weak, deteriorated, cracked, delaminated tunnel liner;<br>. identification of metal structural or functional members such as rebars, pipes, ribs etc.;<br>. identification of thinner tunnel liner areas;<br>. identification and mapping of voiding behind the liner.<br>All data are displayed in the field for quality and recorded on digital disks for future analysis,<br>processing and playback on analog chart recordings for on-site interpretation.<br>The seismic/sonic/ultrasonic measurements provide data to calculate the moduli values (Young’s, bulk<br>and shear) and an evaluation of the strength/mechanical properties of tunnel liner materials (concrete<br>and masonry). The seismic/sonic/ultrasonic results identify and quantify areas of interior<br>deterioration, as well as liner thinning and voiding behind the liner. Radar profiling is used to<br>identify metal within the liner, areas of increased moisture or water infiltration, as well as water filled<br>void conditions behind the liner.<br>This system has been utilized on a number of projects throughout the United States and abroad<br>including: rapid transit, water supply, railway, automobile, and hydroelectric tunnels as well as<br>pipelines.