岩石内の爆轟ヒズミ波形の測定に関する研究
1958 年 74 巻 839 号 p. 277-282
詳細
1958 年 74 巻 839 号 p. 277-282
We have been studying the properties of strain waves in rock produced by the detonation of explosives. Rately, we get some fundamental values of the shapes of strain waves on research tests in Tertiary tuffaceous sandstone at Okitsu, Chiba prefecture, by using a Brown tube oscillograph (6 elements).
1. A strain wave propagates into rock neighbouring the explosive charge with a velocity having higher speed than the sound velocity in rock.
2. The propagation speed falls gradually with the distance from, the detonation point and reaches to the sound velocity, which is 2500m/s in this sandstone.
3. Though the strain waves get out of shape easily by the circumstances, the general shapes are non-oscillating waves having 0.2-4.5ms duration and 1-4m wave length.
4. Strain values are 2×10-4-0.05×10-4 within 1-6m distances from the detonation source under this test conditions, i. e. in soft Tertiary tuffaceous sandstone, 25-50g conventional explosives, 35mmφ bore hole, etc.
Strain is inversely proportional to 1.5 power of the distance.
