基于直流电法的采动围岩应力分布探测研究

发布时间：2018-07-02 09:58

本文选题：采动应力分布 + 直流电法　；参考：《中国矿业大学》2017年硕士论文

【摘要】：随着煤矿开采深度的增加,受复杂地质条件和开采条件的影响,采动围岩应力分布及变化越来越复杂,对巷道支护及煤岩动力灾害影响极大,有效探测采动围岩应力分布及变化显得尤为重要。针对缺乏有效的采动应力分布探测手段,本文提出利用直流电法技术进行采动围岩应力分布探测的思路,分析基于直流电法的采动围岩应力分布及变化探测原理,实验测试分析煤样在不同应力和裂隙等条件下煤层视电阻率的响应规律,现场测试分析采动围岩应力分布的电法响应规律,并进行验证。(1)分析了直流电法探测采动围岩应力分布的原理。直流电法探测以煤岩体的导电性差异(即煤岩体电阻率)为基础,煤体导电特性与孔裂隙分布的演化是决定煤岩体受载过程中电阻率变化特征的主要因素,干燥煤岩体主要以电子导电为主,不同应力水平作用下的煤体,其内部孔裂隙分布不同,从而表现出不同的视电阻率响应规律,即:卸压区内,宏观孔裂隙大量分布,视电阻率值最大,应力集中区内,原始孔裂隙大量闭合,视电阻率最低,原始应力区内孔裂隙不受采动影响,视电阻率大小介于卸压区和应力集中区之间。(2)实验测试和分析了不同应力水平和孔裂隙条件下煤岩体视电阻率的响应规律,发现:加载初期,视电阻率随应力增加而降低;加载中期,视电阻率随应力增加而小幅增大,加载后期至破坏,随应力增大视电阻率呈倍数增大。(3)利用直流电法探测手段对糯东煤矿11702工作面回风顺槽动压区进行了探测,发现工作面前方超前卸压带在距回采面0m~15m范围内,巷道松动圈范围约为距煤壁0m~4m,应力集中带一般为4m~9m。结合电磁辐射技术及钻屑量指标技术对探测结果进行了测试对比验证,表明直流电法技术可以用来探测采动围岩应力的分布状况。与传统测试方法相比,直流电法探测具有高效、快捷的优势,其区域性探测结果更加的全面、直观。
[Abstract]:With the increase of mining depth and the influence of complex geological conditions and mining conditions, the stress distribution and variation of mining surrounding rock is becoming more and more complex, which has a great impact on roadway support and coal and rock dynamic disasters. It is very important to detect the stress distribution and change of mining surrounding rock effectively. In view of the lack of effective detecting means of mining stress distribution, this paper puts forward the idea of detecting the stress distribution of mining surrounding rock by using direct current method, and analyzes the stress distribution and change detection principle of mining surrounding rock based on DC method. The response law of apparent resistivity of coal seam under different stress and fissure is analyzed by experiment, and the electric response law of stress distribution of mining surrounding rock is analyzed by field test. The main results are as follows: (1) the principle of detecting the stress distribution of mining surrounding rock by DC method is analyzed. Based on the difference of electrical conductivity of coal and rock mass (i.e. coal and rock resistivity), the electrical conductivity of coal body and the evolution of pore and fissure distribution are the main factors that determine the change of resistivity during the loading process of coal and rock mass. The dry coal and rock mass are mainly electrically conductive, and the distribution of internal pores and fractures in the coal body under different stress levels is different, thus showing different apparent resistivity response laws, that is, large distribution of macroscopic pore fractures in the pressure relief zone. The apparent resistivity is the largest, and in the stress concentration area, the original hole fissure is largely closed, the apparent resistivity is the lowest, and the hole fissure in the original stress zone is not affected by mining. The apparent resistivity is between the relief zone and the stress concentration area. (2) the response law of apparent resistivity of coal and rock mass under different stress levels and pore fractures is tested and analyzed experimentally. It is found that the apparent resistivity decreases with the increase of stress at the initial loading stage; In the middle period of loading, apparent resistivity increases slightly with the increase of stress, and from the later stage of loading to failure, and increases in multiple with the increase of stress. (3) the dynamic pressure area of return air in 11702 face of Naodong Coal Mine is detected by means of direct current method. It is found that in the 0m~15m range from the mining face in front of the working face, the loosening zone of the roadway is about 4 m from the coal wall, and the stress concentration zone is generally 4 m ~ 9 m. Combined with electromagnetic radiation technology and drilling chip quantity index technology, the test results are compared and verified. The results show that the direct current method can be used to detect the stress distribution of mining surrounding rock. Compared with the traditional testing method, DC detection has the advantages of high efficiency and fast, and its regional detection results are more comprehensive and intuitive.
【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】：TD326

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