大口径レーズドリルの開発と情報化施工

抄録

Raise-drilling is commonly used as a mechanical method for drift excavation of shaft construction in Japan. The practical application of the machine to drift excavation is from Φ 800-1, 750mm in diameter of drift to date. At the Okutataragi underground power station project, the use of small diameter drilling machine was likely to cause the blockade in the drift for the surge tank shaft excavation and become a serious construction trouble. Then, a large caliber raise-drilling (Φ 3, 412mm) machine was newly developed, and applied to drift excavation of the shaft. Prior to the reaming drilling, excavation and drilling data were intensively collected at pilot bore excavation, and analyzed. Then, the reaming drilling Φ 3, 412mm was executed based on those analysis. The paper describes the development of large caliber raise-drilling machine for shaft excavation, and demonstrates that the excavation of the shaft of l=137m is successfully completed by the machine.