深凹露天铁矿隐伏空区三维激光探测技术方法应用研究

Three-D laser scanning approach to the concealed goaf under an open-pit iron mine

针对深凹露天铁矿采坑内隐伏空区的精准探测技术难题,选择鞍本地区的BIF型富铁矿床深凹露天采坑隐伏空区为研究对象,结合前期的物探和钻探空区探测成果,以钻孔式三维激光扫描探测技术为手段,对露天铁矿1号深坑采区+162 m标高采矿平台进行了空区三维激光探测技术应用研究。结果表明,+162 m标高采矿平台隐伏空区面积达7 000 m^2,空区体最大高度16 m,并在+152 m标高采矿平台超前预警空区存在。该三维激光探测技术克服了物探的狭小探测空间限制和钻探的"一孔之见"弊端,可以准确测量隐伏空区的大小、埋深、形状、走向和边界等特征参数,精度达厘米级;三维激光探测技术通过地学建模软件构建空区三维虚拟实体,可使空区表现定量化、可视化和数字化,还可对综合探测采矿平台边界外的区域进行空区超前预警探测。因此可为含空区采矿平台的风险评价、安全处理和优化采矿设计提供可靠的定量数据和理论依据。

The paper intends to choose the goafs of BIF-type iron ore deposit in Anshan-Benxi area( Liaoning) as its research object to solve the technical problem of precise detection of the concealed goafs in the deep open-pit iron mine. And,then,it would like to collect the point data through surface modeling with 3D laser technology as the pulse laser ranging technology as a virtual entity model for the goaf mining. As is known,a lot of concealed goafs has been formed in the underground disordering mining cases that may threaten production safety of the open-pit mining,especially in the deep open-pit ones. It is just to solve such a kind of technical controversy that we have made scanning of the mining platform #162 m elevation in No. 1 deep open-pit mining area of the said open-pit iron mine by using a 3D-laser drilling scanner known as C-ALS( of a scanning hole of 50 mm diameter). Joining the geophysical and drilling exploration results in the early stage,with the help of the 3D-laser drilling scanner named C-ALS( the scanning hole diameter is 50 mm),we have also made it clear that the 3D-laser detection technology is in a position to overcome the limitations of the narrow detection space of the geophysical prospecting and the lop-sided view of drilling. All the testing and measuring work can be well finished accurately by drilling the 3D-laser scanner size,the buried depth,the shape,strike,boundary,the gravel filling condition and all the rest specific parameters of the concealed goafs up to the centimeter level so as to quantify,visualize and digitalize the goafs comprehensively. What is more important is that the advanced warning detection of the goaf outside the boundary of the comprehensive detection mining platform can also be realized. According to the 3D virtual entity calculation of the open-pit mining area of No. 1 deep-pit in the open-pit iron mine,the concealed goafs of the mining platform with the elevation of + 162 m can reach 7000 m^2 with the maximum goaf height being 16 m. The investigation has also found that the filling stuff is mainly ordinary air with a small amount of gravel and a small amount of roof caving. The connectivity of the goaf can be said good enough with only 4 to 5 pillar supports inside. Thus,it can be concluded that the reliable quantitative data can provide a theoretical basis for the risk evaluation,the safety treatment in optimizing the mining platform design in the corresponding areas.