| There are unique advantages of block caving method when exploiting relativelybroken and low-grade ore-body, this method has characteristics of high strength and lowcost compared with other mining methods. In the past decades, many mines at home andabroad have experimented this mining method or put it into practice, accumulated plentyof practical experience and formed corresponding theoretical system. The research andapplication of block caving method involves many factors and aspects, so there are manytechnical problems should be solved. This paper take the “Block caving miningtechnology study of Mount Huangshan copper-nickel mine’s30ththick and large ore-body(above the level of530m)” as the research background, according to the mine’s specificfeatures, based on the work of pre-stage test, investigation and demonstration, conducteda systematic and comprehensive research about the ore-rock cavability and its cavingregularities. The main contents in details as follows:(1) Conducted a series of experiments, measurement and investigation before thefurther study, including indoor rock physical mechanics test, in-situ rock stressmeasurement and engineering geological investigation, and evaluated the rock massquality with the methods of RQD, RMR, Q system and MRMR-2000system respectively,which provide the reliable and comprehensive basic data for the following study.(2) Based on the evaluation results of rock mass quality, made a preliminarycavability assessment of rock mass. Meanwhile, made a comprehensive analysis of thefour different kinds of cavability evaluation methods and its results based on the theory ofAHP-Fuzzy, and concluded the reasonable and reliable evaluation results of cavability.(3) Studied the initial caving and continuous caving hydraulic radius of ore-bodyamong the research scope besed on Laubscher’s caving chart and Mathews stability graphapproach, and made an analysis about the undercutting shape according the hydraulicradius.(4) Comprehensive applied the programs of AutoCAD,3DMine and PGEN to modelthe complex geologic body (such as oreboy in this study) of3DEC rapidly, and simulatedthe caving process. According to the qualitative principle of undercutting method andsequence, put forward three kinds of undercutting schemes, monitored and recorded thevariation of force, displacement and caving blocks’volume in the process of undercutting. At last, made a comprehensive comparison of the results, obtained the most suitableundercutting way and sequence, and verified the results of caving area in the section5.2.(5) Based on the results of experiments, measurement, investigation and theengineering design parameters, using the3D visualization fragmentation predictionsystem BCF to study the caving fragmentation in different stages of caving process, andanalysed the possibilities of low and high hang-ups, thus have a systematic andcomprehensive analysis of the fragmentation size and its distribution in the process ofcaving.This paper puts forward a set of research line and process of block caving miningpractice, systematically and comprehensively studied the ore-rock cavability and cavingregularities, and got the corresponding reliable results and conclusions, which have animportant guidance to the caving mining practice. Meanwhile, this research solved thetheoretical and technical problem in the study of cavability systematic evaluation,complicated geologic body rapid modeling of3DEC, numerical simulation of cavingprocess with three distinct element code3DEC, block caving fragmentation and itsdistribution rules. In a word, this paper has great academic significance and value. |
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