典型断层影响下石膏矿采区失稳机理研究

发布时间：2018-11-17 17:25

【摘要】：石膏作为重要的非金属矿产资源,在经济建设中发挥重要作用。随着石膏矿地下开采范围的持续扩大,采场附近不良地质构造被激活,对采区稳定性产生重大威胁,在极端情况下,可能导致采空区失稳,造成重大人员伤亡和财产损失。断层作为不良地质构造的典型代表,对于其影响下石膏矿采区失稳机理研究依旧不足,因此开展对断层影响下石膏矿采区失稳规律的研究有积极意义。依托湖北省自然科学基金(2011CDB433)《采空区危害型石膏矿矿山采动损害机理及控制研究》项目,采取理论分析、数值模拟、室内实验及案例调研相结合的方法,构建黏滑-Kelvin脆性体模型,探究石膏矿断层破坏模式和采区失稳模式,对断层影响下石膏矿采区失稳机理以及地表沉陷模式进行分析研究。论文主要研究成果包含以下几个方面:(1)基于关键层和薄板理论,构建断层影响下石膏矿开采引起地表沉陷盆地模型,得到地表沉陷最大下沉量、垂直方向上的形态参数、断层影响下地表沉陷中心点偏移量的计算公式。(2)通过数值模拟不同工作面推进距离石膏采区,得到石膏采区位移、塑性区扩展及地表沉陷规律,对上述规律进行分析研究,初步得到断层影响下石膏矿采区失稳机理,即远离断层的顶板端部首先产生拉伸破坏,而后传递至矿房中部,引起顶板冒落,最终传导至地表,采区上方地表出现沉陷。同时也对不同断层倾角的石膏采区进行模拟研究,得到采区附近应力场、位移场变化特征。(3)采用理论计算与FLAC3D数值模拟相结合方法对横店石膏矿地下采区失稳塌陷事故进行数值分析。通过顶板应力计算、矿房极限跨度和矿柱安全系数验算,查明断层破坏是导致采区失稳主要原因。构建多工况数值计算模型,对比分析断层、顶板、矿柱的应力和位移变化规律,揭示断层影响下断层、顶板、矿柱的破坏过程和破坏模式。从石膏矿采区失稳灾害形成及演化出发,对断层—采区破坏模型进行深入研究,初步建立断层影响下横店石膏矿开采引起地表沉陷盆地模型。研究成果能够为横店石膏矿采区失稳控制提供理论依据,也为断层影响下地下石膏矿的采区失稳机理的研究提供新的思路。
[Abstract]:As an important non-metallic mineral resource, gypsum plays an important role in economic construction. With the continuous expansion of underground mining area of gypsum mine, the bad geological structure near the stope is activated, which poses a serious threat to the stability of the mining area. In extreme cases, it may lead to the instability of the goaf, resulting in heavy casualties and property losses. As a typical representative of poor geological structure, fault is still insufficient in the study of instability mechanism of gypsum mining area under its influence, so it is of positive significance to study the instability law of gypsum mining area under the influence of fault. Based on the project of Natural Science Foundation of Hubei Province (2011CDB433), "study on Mining damage Mechanism and Control of Hazardous Gypsum Mine in goaf", the method of combining theoretical analysis, numerical simulation, laboratory experiment and case study is adopted. In this paper, a viscosize-Kelvin brittle body model is constructed to study the failure mode of gypsum ore fault and the failure mode of mining area. The mechanism of instability and the subsidence mode of ground surface under the influence of fault are analyzed and studied. The main research results include the following aspects: (1) based on the theory of critical layer and thin plate, the model of surface subsidence basin caused by gypsum mining under the influence of fault is constructed, and the maximum subsidence amount and the vertical shape parameters are obtained. Under the influence of fault, the calculation formula of the displacement of the center point of surface subsidence is obtained. (2) through numerical simulation of the distance from the gypsum mining area to the different working face, the displacement of the gypsum mining area, the expansion of the plastic zone and the law of the surface subsidence are obtained. By analyzing and studying the above laws, the instability mechanism of gypsum mining area under the influence of fault is preliminarily obtained, that is, the roof end which is far from the fault first produces tensile damage, and then passes to the middle of mine house, causing roof caving to fall, and finally transmitting to the surface of the earth. Subsidence appeared on the surface above the mining area. At the same time, the gypsum mining area with different fault dip angle is simulated and the stress field near the mining area is obtained. (3) numerical analysis of unstable collapse accident in underground mining area of Hengdian gypsum mine is carried out by combining theoretical calculation with FLAC3D numerical simulation. Through the calculation of roof stress, the limit span of mine house and the safety factor of pillar, it is found that the failure of fault is the main cause of instability in mining area. The stress and displacement of faults, roof and pillar are compared and analyzed in order to reveal the failure process and failure mode of fault, roof and pillar under the influence of fault. Starting from the formation and evolution of unstable disasters in gypsum mining area, the failure model of fault-mining area is studied in depth, and the model of surface subsidence basin caused by Hengdian gypsum mining under the influence of fault is established preliminarily. The research results can provide a theoretical basis for the control of instability in the mining area of Hengdian gypsum mine and a new idea for the study of the instability mechanism of the underground gypsum mine under the influence of faults.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD327

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