Study on rapid excavation technology for hard rock roadway in coal mine

In order to improve excavation speed of hard rock tunnel in the end-located drainage roadway of No.4306 mining face of Changping Coal Mine, avoid affecting the gas extraction of No.3 coal seam and improving its recovery rate, a tunnel blasting scheme was designed by drilling-blasting method on the basis of medium-deep hole theory, the structural and strength characteristics of the surrounding rock. A set of highly efficient CMZY2-120/18 drilling-loading unit that could perform hole-drilling and gangue-loading at the same time was selected as rapid tunnel excavation equipment. For this scheme, it was necessary to identify blasting difficulty of the surrounding rock category of the tunnel. The blasting parameters were optimized by ANSYS LS-DYNA numerical simulation, and a scientific organization and management mode of construction with multi-process and parallel-cross operation was adopted. The results showed that Changping Coal Mine had successfully used the CMZY2-120/18 Drilling-Loading Unit, and its hole drilling and mucking were fast and highly efficient, thus reducing the working procedure time. Meanwhile, the tunnel supporting efficiency had improved by about 25% and the average daily drilling distance had increased from 3.2 m to 5.3 m, which largely reduced excavation cost and enhanced the operation environment. Therefore, to strictly follow the normal cycle and parallel-cross operation of each procedure will help improve the efficiency of rock excavation.