Blasting test of underground workshop's rock anchor crane beam for Jinping Secondary Hydropower Station

For formation of a better quality rock bench in the blasting excavation of an underground workshop's rock anchor crane beam for the Jingping Secondary Hydropower Station,optimization of drilling and blasting parameters as well as the charging constitution was carried out through extensive comparative tests with different schemes and blasting vibration monitoring.The results indicate that the blasting effect of 30 cm hole spacing is better than that of 40 cm hole spacing.Furthermore,the coupling coefficient of 30 cm hole spacing is also greater than that of 40 cm hole spacing.Therefore,an increased coupling coefficient could lead to a smoother rock surface and less damage induced by the blasting vibration.