PREDICTING AHEAD OF THE FACE

This paper describes the Tunnel Seismic Prediction (TSP) technique, and gives case histories of its application in various parts of the world. Amberg Measuring Technique has patented this compact, versatile, easy-to-use measurement and evaluation system for moderate to hard rock tunnelling environments. TSP is an underground reflection technique, specially developed for more effective and rapid geological and geotechnical prediction ahead of the face. It fulfils planning and monitoring tasks in a variety of underground sites, and uses the principle of seismic echo sounding. TSP can save impressive amounts of time and money in tunnel construction. Its dependence on the physical properties of rock as a function of wave velocity and rock density make it a powerful interpretation technique. Its potential still remains to be used fully, by using the advanced algorithms and computing technology available today. The article describes the use of TSP in the following tunnelling projects: (1) the Vereina rail tunnel in the High Alps of Switzerland; (2) the Gorigamine bullet train tunnel in Japan; (3) the Kazunogawa Hydro tunnel in Japan; and (4) the Anmin road tunnel in South Korea. A table gives various statistical figures about the tunnels for these and five other case studies.