Numerical Simulation Of Large The Hongshan Two River Pillar Of Iron Ore Stope Surrounding Rock Stability Analysis

This article describes the stoping program of the two river IV3iron ore25-125section and125-225section, these two sections stoping at the same time,and use the point pillar to the level hierarchical filling mining method, in this paper i use the finite differential code FLAC3D to analyse the three-dimensional numerical simulaiton and optimization for the pillars of the surrounding rock in this section.in this paper i use the finite differential code method to analyse the stability and pressure situation of the two river IV3iron ore, meanwhile, I get some results:establish mass models to analyse different stoping sequences,different dimensions of the pillars and situation of interlayer thickness, i also analyse the compartment, stope roof, pressure distribution law of the pillars and the distribution law of plastic zone change.The main conclusions drawn are as follow:through simulation for five porgrams of different stoping sequences,different dimensions of the pillars and different sizes of the compartment thickness, analysis on the safe production and improve resource recovery. The results show that program2is the mining sequence AD-BE-CF,point column is4.5mX4.5m,column thickness is10m,this is the best program.The distincion is not bovious on stability of the stope point column and the stability of the stope roof when we use different stoping sequences.However, if we consider to recycle resources to extend the mine life at the same time, in order to improve the mine priduction efficiency, we’d better choose stope the two sections at same time.due to the presence of point columns, for the five programs, with the increase in the size of the point clolumn, the compressive stress decreases, but the tensile stress increases, the reason is the pillars may partial destruction under the compressive stress.however in these five programs,this is no tensile stress on the roof,so if there is no rock mass affected by joints and falults,the roof is stillrelaticely stable.in the five programs, after F excavation the left side of the compartment stope exist large compressive stress, the reasons maybe are tilted ore body and the stress concentration appears at the corner, we could not mining here.especially,after the A recovery, the corner can not be mined and be filled timely. F recovery, the stress concentration appears at the corner so we could not recovery samely, and we could bolting to guarantee the stability of the compartment to ensure the safety of the production.with the decreasing interlayer thickness, tensile stress value in the interlayer rock is increasing, point column tnesile stress expanded,comprssive stress increases, the distribution of plastic zone expanded. the main factors that affect the stability of the interlayer rock are the strength of the rock mass itself and the span of the panel.therefore, in order to maintain the stability fo the interlayer rock, we should control the span of the panel,and the point column is benefit to the stability of the interlayer.through the nonlinear calculation, in the five programs, after mining the stope roof,floor,pillars and the surrounding rock appears the shear yield in each stope.the stability of the pillars are not noly relate to the pillars themselve,but also the highth of the pillars.therefore, when we mining,each section is not too high,thickness of the pillars could decrease in order to impove the source recycle efficiency.