地下采矿引起的程潮铁矿东区地表变形规律研究

金属矿山由于其矿体形态多变、地质条件复杂、多非充分采动、开采方法多样、构造应力显著及结构效应明显等特点，难以把握由地下采矿引起的地表变形和岩体的破坏形式。以程潮铁矿东区为例，依据近年（2010年3月至2015年9月）的地表变形实测数据，绘制出相应的监测成果图。结合三维激光扫描等新技术再现地表变形三维盆地，探究了地下开采影响下的地表变形规律和机制。对矿区上下盘地表变形规律等进行了比较分析，结果表明：程潮铁矿东区在采矿初期发生筒状冒落；变形传递到地表后，在采空区正上方形成大小不等的漏斗状塌坑群。上盘地表变形扩展与采矿推进度有较好的对应关系；水平应力是岩体变形的主动力，应力不断释放影响着地表变形特征。结构面倾向改变了上、下盘岩体的破坏形式，减缓和加速了上下盘岩体的破坏。同时，在坡体形态的影响下，地表变形在下坡方向总变形量增大和垂直变形增量更大。

Ground movement and deformation caused by underground mining in eastern area of Chengchao iron mine

It is challenging to represent the surface deformation characteristics and the rock mass failure modes caused by underground mining, since there are many uncontrolled factors such as variational orebody shapes, complex geological conditions, mostly subcritical excavation, different mining methods, conspicuous tectonic stress and obvious structure effect. In this study, the eastern area of Chengchao iron mine was selected as an example, and monitoring results were achieved by 3D laser scanning and GPS surveying based on the first-hand monitoring data of surface deformation from March 2010 to September 2015. Thus the surface deformation characteristics and rock mass failure mechanisms caused by underground mining were explored. The comparative analysis of surface deformation in the hanging wall and on the footwall of eastern area of Chengchao iron mine showed that: tubular caving continuously developed upwards at the beginning of the mining. Different sizes of funnel-shaped collapse pits appeared on the mined-out area surface after the rock mass caving propagated to the ground. The extension of surface deformation was consistent with the mining advance in the hanging wall. Furthermore, the surface deformation characteristics were mainly affected by horizontal stress which served as a main driving force of rock mass deformation. Additionally, the damage modes of rock mass were changed by the structural plane, which mainly slowed down and accelerated rock mass deformation in the hanging wall and footwall, respectively. Moreover, the total deformation and the vertical deformation rate were much greater in the downward direction due to the slope morphology.