くさび形ビットおよびローラカッタによる高温岩石の破壊について
機械掘削における岩石の破壊機構について (第4報)
1978 年 94 巻 1080 号 p. 69-76
詳細
1978 年 94 巻 1080 号 p. 69-76
Rock excavation tests were carried out at elevated, temperature with wedge bit to clarify the fracture mechanism of hot rock for the development of geothermal energy. It was proved that the Ioad required to create a shear crack and the crater shape by wedge penetration agreed well with the theoretical prediction developed when sandy tuff and andesite were used, while tensile cracks were initiated rather than shear crack for marble at more than 200°C which was substantiated by both experiments and theory.
Rock cutting tests were also performed with gear cutter and disk cutter using the linear cutter apparatus equipped with electric furnace at 200°C, 400°C and 600°C. During the experiments the load on the cutter was kept at 500kg and crater depth and tangential cutter force were measured. The crater shape was compared with the theoretical fracture paths developed by wedge bit penetration and close agreement was obtained between them.
