抄録
Horizontal seismic profile method was tested at a tunneling site of the Toyoha mine for exploring the geologic conditions beyond the working face. The conclusions acquired are as follows; (1) it is very difficult to acquire P-wave reflections, (2) walls of cavities are free planes and thus it is difficult to obtain pure P-wave signals, (3) it is easy to obtain S-wave signals by "free walls". In this report we propose that HSP be carried out by using S-waves rather than P-waves.
