官庄铁矿深埋破碎矿体开采岩体变形测试分析

MEASUREMENT ANALYSES OF ROCK MASS MOVEMENT AND DEFORMATION DUE TO UNDERGROUND MINING OF DEEP FRACTURED OREBODY IN GUANZHUANG IRON MINE

以大量实测资料为基础,分析官庄铁矿北区深埋破碎厚矿体开采引起的围岩变形和地表移动规律。实测结果表明,官庄铁矿北区地表下沉属于连续下沉,岩层破坏主要是缓慢型破坏。分析过程中,把几种实测分析方法和数值分析法有机结合在一起,形成岩体移动变形综合研究方法,对地下开采引起的岩体移动机制进行具体分析。分析中所采用的实测分析类方法包括蠕变试验分析、地表移动观测分析、围岩变形监测分析、原岩应力量测分析;数值分析类方法包括ANSYS和FLAC。结合官庄铁矿工程实例,通过具体测试分析,探讨深部开采岩体移动变形规律及特点,即深部开采覆岩移动变形具有均匀、整体压缩变形等特点,地表移动连续且周期较长。实践证明,所采用的综合研究方法是分析岩体移动和地表下沉机制的有效途径。

It is the purpose of this paper to discuss the problem of rock mass displacement and deformation due to deep underground mining of fractured thick iron orebody.The laws of ground surface subsidence and rock mass movement and deformation in north area of Guanzhuang iron mine due to deep underground mining are studied.The ground surface subsides continuously;and rock mass fails slowly in the mine.Based on the ground surface subsidence and surrounding rock deformation monitoring and numerical simulation methods,a comprehensive method is put forward to analyze the displacement and deformation mechanism of rock mass due to underground mining.Several measurement and analytical methods have been given for predictions and analyses of rockmass dispacements and deformations due to deep mining of fractured thick iron orebody.They are classified as meaurement methods（creep analyses,ground movements analyses,surrounding rock deformations analyses and in-situ stress measurements） and numerical methods（ANSYS and FLAC）.New monitoring data have been analyzed to study the rock mass deformations due to deep mining of fractured thick iron orebody in Guanzhuang iron mine.It has also been compared to the results obtained by numerical analyses.By mechanical analysis as well as case study,rock mass deformation and ground subsidence caused by the deep iron ore mining are studied.The results show that the displacements of overburden layer are characterized by uniform and entire compression,displacements and deformations.The laws of surface subsidences are that the surface deformations are continual and slow with a long last period of movement.A case study shows that this method is an available approach to investigate the mechanism of rock mass deformation and ground surface subsidence.