石膏矿大型采空区突变失稳机理及稳定性研究

发布时间：2018-04-18 04:35

本文选题：石膏矿山 + 房柱式开采　；参考：《中国矿业大学》2017年硕士论文

【摘要】：在我国石膏矿山普遍采用房柱式采矿方法进行开采,由于超高超宽开采或设计不合理,相继发生了采空区顶板崩落、矿柱倒塌、地表岩移等现象,农田、村庄、建筑物、交通水利设施等遭受破坏,个别矿山甚至发生了人员伤亡等极为严重的事件。本文针对苏北石膏矿大面积采空区稳定性问题,综合运用现场调研、实验室测试、理论分析及数值计算的研究方法,对石膏矿矿柱及顶板稳定性、采空区链锁式失稳反应机理以及大面积悬露顶板的稳定性等进行了系统研究,主要研究成果如下:(1)通过实验对石膏岩样进行了研究,采用电子万能试验机对岩样单轴抗压强度、单轴抗拉强度和抗剪强度进行了测试,并根据测试结果进行拟合分析,得到石膏岩体弹性模量、泊松比、粘聚力及内摩擦角等参数,为采空区稳定性理论分析以及数值模拟提供基本参数。(2)在考虑围岩破坏特征的基础上,通过建立石膏岩体损伤演化模型,引入形状参数,得出了石膏岩体改进的损伤本构方程;基于突变理论并结合石膏岩体的损伤本构方程推导出矿柱的尖点突变方程,得出矿柱的失稳判据。通过对顶板及矿柱变形和破坏特征分析,结合薄板理论,建立矿房顶板及矿柱力学模型,揭示石膏矿矿房矿柱破坏规律。(3)根据矿柱载荷和矿柱强度的相互关系,计算出矿柱的安全系数,提出了采空区链锁式反应的动态计算方法。在此基础上建立了采空区大面积悬露顶板的托板力学模型,分析矿柱失稳后形成的大面积悬露顶板的应力分布特征,根据顶板稳定性判据确定顶板的稳定性。(4)结合苏北石膏矿地质特征,对采空区和巷道的地质形态进行分类,运用Flac3D对典型区域进行模拟;运用链锁式动态计算方法和托板理论对矿柱和矿柱失稳后形成的大面积悬露顶板进行理论计算。计算结果表明,数值计算与模拟计算结果基本一致。
[Abstract]:In the gypsum mine of our country, the roof caving of goaf, the collapse of pillar, the movement of surface rock and so on, farmland, village, building and so on, have occurred because of super wide mining or unreasonable design.Transportation and water conservancy facilities have been damaged, and some mines have even suffered casualties and other extremely serious incidents.Aiming at the stability of large area goaf in the gypsum mine of northern Jiangsu, the stability of pillar and roof of gypsum ore is studied by using the methods of field investigation, laboratory test, theoretical analysis and numerical calculation.The mechanism of chain instability in goaf and the stability of large area hanging roof are studied systematically. The main research results are as follows: 1) the gypsum rock sample is studied through experiments, and the uniaxial compressive strength of rock sample is studied by electronic universal testing machine.The uniaxial tensile strength and shear strength are tested, and the elastic modulus, Poisson's ratio, cohesion force and internal friction angle of gypsum rock are obtained by fitting and analyzing according to the test results.On the basis of considering the failure characteristics of surrounding rock, the damage evolution model of gypsum rock mass is established and the shape parameter is introduced, and the improved damage constitutive equation of gypsum rock mass is obtained.Based on catastrophe theory and damage constitutive equation of gypsum rock mass, the cusp catastrophe equation of pillar is derived, and the instability criterion of pillar is obtained.Based on the analysis of the deformation and failure characteristics of roof and pillar, combined with the theory of thin plate, the mechanical model of roof and pillar is established, which reveals the failure rule of pillar in gypsum mine. (3) according to the relationship between pillar load and pillar strength,The safety factor of pillar is calculated, and the dynamic calculation method of chain reaction in goaf is put forward.On this basis, the mechanical model of large area suspended roof in goaf is established, and the stress distribution characteristics of large area suspended roof formed after pillar instability are analyzed.According to the criterion of roof stability, the roof stability is determined. (4) combined with the geological characteristics of gypsum ore in northern Jiangsu, the geological forms of goaf and roadway are classified, and the typical area is simulated by Flac3D.The dynamic calculation method of chain type and the theory of supporting plate are used to calculate the large area suspended roof formed after the instability of pillar and pillar.The results show that the numerical results are in good agreement with the simulated ones.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD325.3

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