摘要
地下矿山采用空场法或崩落法开采时,空区顶板岩层冒落至地表后,引起的岩移对地表工业设施及环境构成了严重威胁,临界散体柱理论的提出为地表岩移控制提供了新思路。以锡林浩特萤石矿急倾斜中厚矿体浅孔留矿法开采现状作为工程背景,通过现场监测调研与相似物理试验,研究了临界散体柱的主要影响因素。结果表明:①临界散体柱高度随着矿体倾角增加而减小,随着井下放矿的进行,松动散体柱高度仅为散体总高度的39.4%~45.7%,其上方密实散体柱对于限制岩移起主要作用;②针对不同的矿体厚度,通过增加散体充填高度降低厚跨比,可控制地表塌陷范围;③围岩适当变形可以增加散体的被动侧压力,降低塌陷坑边壁岩体稳定所需的临界散体柱高度;④塌陷坑散体结拱特性受散体粒径分布与塌陷坑宽度的共同影响,控制着临界散体柱的有效作用高度,锡林浩特萤石矿散体临界结拱粒径范围为0.5~0.7 m,临界结拱宽度为3.5~4.0 m,远小于塌陷坑的实际分布宽度,即散体能够保持连续流动,表明临界散体柱理论能够较好地应用于锡林浩特萤石矿。
When underground mines are mined by the open stpoe method or the caving method,the roof will cave.After the caving of the roof strata has developed to the surface,the rock movement will pose a serious threat to the surface industrial facilities and the environment.The theory of critical medium column provides a new idea for surface rock movement control.Taking the mining status of the Xilinhaote Fluorite Deposit with the steeply inclined medium-thick orebody which using shorthole shrinkage method as the engineering background,the main influencing factors of the critical bulk column are studied through field monitoring investigation and similar physical tests.The results show that:① The height of the critical medium column decreases with the increase of the dip angle of the ore body.With the progress of the underground ore drawing,the height of the loose body column is only 39.4%~45.7% of the total height of the bulk,the dense scattered columns above it play a major role in restricting rock movement.② For different ore body thicknesses,by increasing the filling height of the scattered body and reducing the thickness-span ratio,the surface subsidence range can be controlled.③ Proper deformation of the surrounding rock can increase the passive side pressure of the bulk,and reduce the critical medium column height required for the stability of the rock mass of the collapse pit.④ The arch characteristics of the collapse pit are affected by the granularity of the bulk and the collapse pit width,and control the effective height of the critical medium column.The critical arch size range of the Xilinhot Fluorite Deposit is 0.5~0.7 m,and the critical arch width is 3.5~4.0 m,which is much smaller than the actual distribution width of the collapse pit,that is,the bulk can maintain continuous flow.The above discussion result further indicated that the critical medium column theory can be well applied to Xilinhot Fluorite Mine.
作者
张东杰
任凤玉
郑有伟
ZHANG Dongjie;REN Fengyu;ZHENG Youwei(Institute of Mining and Coal,Inner Mongolia University of Science&Technology,Baotou 014010,China;School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China)
出处
《金属矿山》
CAS
北大核心
2020年第9期72-79,共8页
Metal Mine
基金
国家自然科学基金项目(编号:51264028)
内蒙古自然科学基金项目(编号:2018LH04001)。
关键词
地下开采
临界散体柱
厚跨比
岩移控制
散体结拱特性
underground mining
critical medium column
thickness-to-span ratio
rock movement control
granular media arching characteristics
