基于PFC2D自然崩落法数值模拟

云南普朗铜矿是一个新建的大型铜矿山,矿山设计采用自然崩落采矿法。自然崩落法底部结构受力规律尚不明确,为了研究矿山开采中底部结构受力变化,采用PFC2D数值分析软件,针对普朗铜矿3720水平首采区地质条件及岩体物理力学参数建立计算模型并简述了岩体微观参数与宏观参数之间关系。同时模拟分析三种拉底宽度及放矿过程中底部结构应力变化规律。结果表明：三种拉底宽度下,应力重分布后应力集中区范围集中拉底推进线前方50m-80m内,应加强支护。随着拉底宽度的增大峰值应力随之增大,在45m拉底宽度下最大应力达到22MPa。在放矿时,放矿漏斗侧壁及眉线处会产生高动态应力不利于底部结构的长期服役。研究所得结果对矿山支护起到指导作用。

Numerical Simulation of Natural Caving Mining Method Based on PFC2D

Yunnan Pulang Copper Mine is a new-built large mine which was mined by natural caving mining method. The laws of stress variation of the bottom structure remain unclear. Adopt the software PFC2D to analyze the stress variation of the bottom structure during the mining process, set up calculating model which based on the geological conditions of the first mining area of 3720 level in Pulang Copper Mine as well as physical and mechanical parameters, and briefly introduce the relationship between microscopic and macro parameters of rocks. At the same time, stimulate and analyze the variation laws of three kinds of undercut width and the stress of the bottom structure during the ore drawing process. Results indicate that under the condition of three kinds of undercut width, after the redistribution of stress, the stress concentration zone should be in front of the advance line where ranges from 50m to 80m, and the support should be strengthened. The peak stress increases along with the width of undercut, and reaches the maximum 22MPa with 45m undercut width. In the process of ore drawing, the high dynamic stress will emerge at the side of the funnel and the bench edge, which is not conducive to the long-term service of the bottom structure. The results of the study play a guiding role in mine support.