Abstract: There is a general tendency to use continuous mining in underground metal mine. Non-pillar continuous mining(NPCM) was briefly introduced as an example of a new continuous mining method in a copper mine. Its technological concept and its excavation plan were outlined. Three-dimensional finite element numerical method was employed to simulate the practical excavation and backfilling mining activities. Stability status (including stress and displacement) was analyzed and proper measures to control the ground pressure were presented. These measures are as follows: 1) attention to manage the stope's roof should be focused on the roof near the hanging wall;2) the strength and stiffness of backfilling in the lower part of stope should be greater than that of backfilling in the upper part;3) there exists localized stress concentration in the temporary pillar and temporary ore-wall during the whole process of excavation;4) control blast technique should be employed to excavate the temporary ore-wall and the ore body near the temporary ore-wall.
Ground pressure and control techniques in non-pillar continuous mining method
Abstract:
There is a general tendency to use continuous mining in underground metal mine. Non pillar continuous mining (NPCM) was briefly introduced as an example of a new continuous mining method in a copper mine. Its technological concept and its excavation plan were outlined. Three dimensional finite element numerical method was employed to simulate the practical excavation and backfilling mining activities. Stability status (including stress and displacement) was analyzed and proper measures to control the ground pressure were presented. These measures are as follows: 1) attention to manage the stope's roof should be focused on the roof near the hanging wall; 2) the strength and stiffness of backfilling in the lower part of stope should be greater than that of backfilling in the upper part; 3) there exists localized stress concentration in the temporary pillar and temporary ore wall during the whole process of excavation; 4) control blast technique should be employed to excavate the temporary ore wall and the ore body near the temporary ore wall.
Fig.1 Profile of experimental scheme of NPCM1—Basement structure; 2—Vertical deep blasthole; 3—Temporary ore wall; 4—Backfilling in stope; 5—Temporary pillar; 6—Drilling roomL1—Length of stope Ⅰ; L2—Length of stope Ⅱ; L3—Width of ore-body; H—Height of level
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