EXPERIMENTAL STUDY ON BLASTING EXCAVATION OF ROCK BENCH FOR CRANE BEAM IN UNDERGROUND WORKSHOP

In order that rock bench for crane beam is excavated by blasting in complex geological condition,the excavation schemes such as smooth blasting with vertical or horizontal holes and presplitting with vertical holes are tested.Through analyzing and comparing the blasting results of different excavation schemes,the excavation mode and blasting sequence by which the rock bench with a qualified shape can be formed are determined.After blasting,a sonic method is used for measurement of the damage depth of the country rock.Testing results show that the damage depth of the country rock is less and the determined excavation mode and blasting sequence can ensure the safety of the crane beam during its construction and running.