Answer: A, B, D
P38-40
The main methods of straight eye cutting include gap cutting or crack cutting, corner prismatic cutting (Tubular) Grooving, Spiral Grooving and Double Spiral Grooving, etc. Its characteristics are that all cut holes are arranged perpendicular to the working surface, which is conducive to simultaneous operation of multiple drilling rigs and mechanized operations; the depth of blastholes is not limited by the tunnel section, and medium-deep hole blasting can be achieved; a high utilization rate of blastholes can be achieved; rock The throwing distance is short, the explosion is concentrated, and it is not easy to damage the equipment and supporting structures in the shaft wall and tunnel. However, more blastholes are required and the consumption of explosives is higher; the spacing and parallelism requirements for blastholes are also high.