ワイヤーソ工法を利用した硬岩地山トンネルの掘削

抄録

Hard rock tunnels are usually excavated by means of the drill and blasting method. But this may not be allowed due to noise or around vibration problems when the tunnel is located in urban areas or exsisting important structures. Since the number of these cases is increasing recently, the low vibration tunnelling methods are becoming more important.
The mechanical pre-cutting method using a wire saw machine has been developed. The method involves cutting the tunnel perimeter using a wire saw before the latter is excavated by the controlled blasting. This paper describes the outline of the method and its application to the intersection of the two tunnels at the Miharu dam.