Blasting Excavation Technology of Underground Workshop′s Rock Anchor Crane Beam under Complex Conditions

In the blasting excavation of underground workshop′s rock anchor crane beam for Jinping secondary hydropower station,blasting parameters were optimized through repeating blasting excavation test according to the characteristics of poor geological condition and abundant fissure.Moreover,protective layer was reserved,drilling accuracy was controlled and charging constitution was optimized in the blasting construction.The quality of rock bench forming has been acquired.