|SSP||In Sonic Softground Probing a seismic system that is mounted on the cutting wheel of a tunnel boring machine operates automatically while drilling. An electromagnetic shaker excites a broad-band high-frequency (KHz range) sweep signal in the forward direction. The response of the earth is recorded by accelerometers and passed to PCs running Linux. In spite of the noisy environment, automated real-time processing yields a three-dimensional reflection image of the nearest few tens of metres ahead of the cutting wheel. This allows civil engineers to recognize potentially dangerous obstacles or voids and to adjust drilling parameters in time. The SSP is developed together with Herrenknecht AG, Germany. A recent publication on the SSP system can be found in First Break, 18, 295-302.|
|TSP||Tunnel Seismic Prediction is a seismic acquisition and processing system primarily targeted at hard rock. Multi-component receivers mounted in the tunnel wall record seismic waves initiated by small charges of explosives and pass the data to a Windows-PC. Interactive seismic processing with no or with a minimum of parameter settings allows civil engineers to locate P-wave and S-wave impedance contrasts in three-dimensional space few hundred metres ahead. The most prominent reflectors and their intersection points with the tunnel axis are automatically determined within about an hour. The TSP is developed together with Amberg Measuring Technique AG, Switzerland.|
Last updated January 15, 2010. © 2000, Tunnelseis. All rights reserved.