With the gradual increase of mining depth,the engineering geological conditions of deep broken sur-rounding rock mass become complex and changeable,greatly affecting underground projects'construction process and subsequent use period's safety.In order to ensure the safety and quality of deep broken soft rock roadway during the construction process,advanced roof control reinforcement and controlled blasting technology for soft rock roadway were put forward.In view of the characteristics of highly developed fissures and poor stability of rock mass at the No.6 intersection of-550 m level in Zhongjiu iron mine,it was proposed to adopt advanced roof control measures to strengthen the surrounding rock mass of the roof and improve the bearing capacity of deep-buried broken soft rock roadway.In order to facilitate the excavation construction,17 excavation areas were divided along the northeast side of the No.6 intersection,and a four-step method was used for segmented construction.To realize the hole-by-hole shot and reduce the influence of blasting vibration,the detonation interval between two adjacent digital electronic detona-tors was randomly set to 3～5 ms.According to the overall lithology of different excavation areas,the support methods(pipe shed support,W-shaped steel belt,anchor cable support,etc.)were optimized to ensure the safety of the sub-sequent use of the No.6 intersection.The test results show that the advanced roof control reinforcement and con-trolled partition blasting technology can reduce the roof deflection and subsidence of broken soft rock roadway,which ensures the forming effect of the No.6 intersection section and reduces the cost of support and shotcrete by 8.7％.
关键词
破碎软岩/台阶法施工/支护方式/数码电子雷管
Key words
fractured soft rock/bench construction method/support pattern/digital electronic detonator
维普
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