Study On Creep Characteristics And Stability Of Self - Supporting Iron Ore Pillar Based On Structural Reliability

This paper relies on the orebody mining design of Zizou Iron Mine of Ludian mineral company between line 12～line 17 with 1530m～1630m, combines with the various research methods of field investigation, theoretical analysis, numerical simulation and so on, studies the stability of residual pillar in the mining process. At the same time, it analyses and summarizes the relationship between the safety factor and reliability as well as the pillar strength value(Including the intensity decay process), has guiding significance for the selection of safety coefficient in the future design or stability analysis.According to this article, the research achievements are as follows:1, Deepen the understanding of the general steps and calculation methods of the reliability analysis of mine structure, and write a Matlab program of reliability calculation.2, Based on the creep test results, select Xiyuan accelerated model as the most suitable rheological model, and obtained the whole creep curve and long-term strength equation, the long-term strength of pillar value is 1.11Mpa.3, Zizou Iron Mine ore pillar shear strength parameters were statistically analyzed. Among them, the numerical characteristics of cohesive force and internal friction angle are calculated; through hypothesis and test, the distribution of them is in line with the normal distribution.4, By using the strength reduction method, a single interval pillar was simulated intensity decay process. In the simulation process, safety coefficient and reliability values showed obvious nonlinear relationship; In the case that the safety coefficient is constant, with the attenuation of the strength, the reliability is gradually reduced. In the case of the reliability index value is invariable, the reasonable value of the safety factor is increasing with the attenuation of the strength.5, The above conclusions and rules applied to Zizou Iron Mine ore pillar,12# line to 17# line,1530m～1630m, were analyzed on the long-term strength and stability, finally suggest reasonable values of point safety factor is 1.29.