| With the mining of deep ore body in high crustal stress and high temperature graduallypresented, along with rock burst occurred, geological disasters may be induced in the complexgeological environment of deep ore mining. Stope stability of deep mining has become an urgentproblem. According to the theory of elastic-plastic mechanics,modeling of stope roof has beconstructed to analyse theoretically stress and strain of stope roof;Under two step mining,maxlength of the stope has been calculatedin accordance withthe strength of the pillar of fillingbody. Based on the finite difference theory Ashele deep stope structure parameter optimizationand the numerical simulation of stope stability analysis by FLAC3Dsoftware, stress distributionand deformation process of the stope structure have truthfully reproduced. Stress distribution andgeometric deformation characteristics of the stope structure medium have beenmastered.Numerical simulation of deep mining for stope design、 support and management ofproduction safety provides a theoretical basis for the mine safe、high efficient production andscientific management with theoretical significance. Since completion of microseismicmonitoring system, the microseismic monitoring technology has been applyed to analysemicroseismic events to forecast rock burst and large-scale rock fracture in the deep mining bymonitoring the mining area ground pressure activity in real time process.Microseismic events ofstope rock have been analysed to reveal rock damage with energy releasing process of stopesrock mined and changes in structural stability of stope, revealing relationship of stress, strain andenergy variation of surrounding rock for deep stope ore mining for safty production managementto provide a scientific theory. The main conclusions and results are as follows:(1) By engineering geological studies of Ashele deep mine, engineering geologicalcharacteristics of the region and deformation characteristics of ore jointed rock have been studiedby mass quality classification research and evaluation.Owing to joint development of deep rockmass, there are some structural surface and small faults for stope mining with some adverseeffects. In the process of mining, phenomena of rock burst occuring in the deep ore mining ismore negative. Basalt and porphyry rock have good quality, tuff rock quality general.(2) If the rockmass be the continuous medium, rock beam structure model of the stope roofhas been establish by theoretical analysis and calculation. Deflection of the stope roof strata in the horizontal tectonic stress be smaller in the initial stage of stope mining,horizontal tectonic stresshas slowed down the role of deformation of the roof strata to the calculate critical span combinedwith the actual situation of the deep stope roof strata.(3)Through numerical simulation of different mining width of stope, economic reasonableratio of mine and cut、less residual of stope ore and factors of stope stability have becomparatively analysed and synthetically considerated to select the optimal12m mining width ofstope structure.(4) By numerical simulation of every two、every three and every four mining stope in theoriginal rock, deformation of the roof and bottom of tunnel and stope can be seen small, pillardamage degree smaller and collapsing of stope pillar less. By numerical simulation of every two、every three and every four mining stope in the fillingbody, the roof and pillar of the stopebackfilling in every four mining stope appear stabler on the whole,emerging deformation of thesmall partly roof and pillar.(5) The bolting and shotcreting playing fully the role of the surrounding rock self bearingcapacity, construction of the bolting and shotcreting is convenient and rapid, relatively low cost,ensuring the stability of roadways and chambers. Support combined the anchored net、 sprayedconcrete and long anchor successfully solves the stability of stope roof problems in the case ofbroken stope rock.(6) Construction of the microseismic monitoring system of Ashele copper mine has realizedreal-time monitoring microseismic event with higher accurate positioning to analyse the dailymicroseismic event.By using the change of the accumulation volume and event magnitude,theshifting and lowering of a、b value, rock burst or large scale rock cracking accumulation volumewith energy releaseing have effectively predicted. Study of effect of mining field of surroundingrock in mining activities of stopes(300m3#、12#and so on), has demonstrated redistribution ofthe surrounding rock stress and energy accumulation and release presented alternately ofsurrounding rock, the stress and displacement of the whole movement events in the low range, sothat the activity of stope wall rock is not stronger, the stability of the overall stope surroundingrock good. |
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