急倾斜中厚矿体开采引发的岩体移动规律模拟实验

Experimental on Rock Mass Movement Law Caused by Steeply Inclined Medium-thick Ore Body Mining

急倾斜中厚矿体开采过程中,不同采深下崩落区开采引起的周边岩体移动趋势对诱导冒落法的安全使用起到至关重要的作用。以双鸭山铁矿诱导冒落法开采为工程背景,采用相似材料实验方法模拟了400、600、800、1000 m采深下,矿体及近矿上、下盘围岩受开采扰动的影响。研究表明:400~1000 m采深条件下,矿体及近矿上、下盘围岩均呈现压密→滑移→压密的现象,且放矿对顶板矿岩受扰动的影响较大;矿体水平位移变化相较于近矿上、下盘围岩位移变化更剧烈,同时上盘围岩较下盘围岩对放矿的扰动更敏感;随采深的增加,矿体及近矿上、下盘围岩水平位移和垂直位移均出现由指向采空区转变为背离采空区的现象,且矿体总位移和应变波动范围均增大。

In the extraction of medium-thick ore bodies with steep inclines,the movement trend of the surrounding rock mass within the caving area,influenced by mining activities,significantly impacts the effectiveness of the induced caving method.The induced caving mining of an iron mine was taken as the engineering context,and the similar material experiment method was employed to simulate the impact of mining-induced disturbances on the ore body and the surrounding rock of the upper and lower plates at depths below 400 m,600 m,800 m,and 1000 m.Research indicates that at mining depths ranging from 400 to 1000 meters,the ore body and the surrounding rock of the mine s upper and lower walls exhibit a sequence of compaction,slippage,and subsequent compaction.Ore extraction significantly influences the disturbance of the roof rock.The horizontal displacement of the ore body is more pronounced than that of the surrounding rock near the upper and lower walls of the mine,with the upper wall s surrounding rock being more responsive to the disturbance caused by ore extraction than the lower wall s.As the mining depth increases,the horizontal and vertical displacements of the ore body and the surrounding rock of the upper and lower plates near the ore body shift from being directed towards the goal to deviating from it.Moreover,the total displacement and strain fluctuation range of the ore body are observed to expand.