关键词: 两步回采, 破碎岩体, 逐孔爆破, 进路充填

Abstract: The upward drift stoping with backfill for instable rock mass in Nanren iron mines area was ineffective and unsafe.In view of this situation，based on the on-site inspection，test and numerical simulation，the downward two-step drift stoping with upward backfill method that keeps the roof area invariable was put forward.Combining of the optimization of roof support with hole-by-hole blasting，the on-site tests were carried out.The results indicated that this new method could simplify the construction process，improve the mining efficiency and the stoping safety.Therefore，it has demonstration significance for safely and effectively mining of instable broken rock mass in this district.

Key words: Two-step stoping, Broken rock mass, Hole-by-hole blasting, Drift backfilling