含水煤样剪切破坏损伤规律试验研究
发布时间：2018-11-28 10:16
【摘要】：西部矿区逐渐成为我国煤炭资源开发的重点,但水资源的匮乏却成为制约当地煤炭资源开发的瓶颈。因此,煤水共采已刻不容缓,而目前煤水共采方法主要包括保水开采和地下水库技术,尤其是地下水库技术已在神东矿区大规模推广应用。地下水库的稳定性与人工坝体和煤柱坝体的稳定性密切相关,其中煤柱坝体的失稳破坏不仅与其所受的荷载相关,亦受到水的侵蚀作用的影响。因此,研究不同含水率下煤样的剪切破坏特征,对揭示地下水库煤柱坝体在水作用下的变形特征有着重要意义。论文以含水煤样剪切破坏损伤规律为主要研究对象,通过压剪试验对煤样剪切破坏强度及特征参数进行系统研究。利用声发射及红外辐射等研究手段对不同含水率下煤样剪切过程进行反演和分析,得到不同含水状态下煤样剪切破坏声发射及红外辐射特征,并以此为建立模型,对含水煤样剪切破坏过程损伤规律进行分析。论文从吸水性实验入手,首先确定5个浸水时间点;通过剪切试验表明随着含水率的升高,煤样的抗剪强度逐渐降低,二者之间呈指数降低的关系。并对剪切强度参数c、φ进行分析得出,煤样浸水后二者均呈下降趋势,同时基于含水率对摩尔库伦破坏准则参数进行修正;通过对试样剪切过程声发射参数研究,得到声发射计数及能率特征与应力应变曲线变化趋势具有相关性,即随着含水率的升高,声发射计数及能率特征越不明显;通过对剪切过程红外特征参数AIRT的分析,得到随着含水率增加,AIRT温变幅度不断降低,最高及最低辐射温度呈现相同的趋势。并结合表面辐射温度熵及方差等参数,得到含水率越高,表面温度方差越小的趋势;通过建立以声发射计数特征为基础的整体损伤变量以及以红外辐射温变点为基础的表面损伤变量。得到整体损伤变量在反映煤样更具前兆性和阶段性,而表面损伤变量则在峰值破坏阶段与应力-时间曲线拟合度更高。最后对煤样剪切破坏损伤模型作出评价,为研究坝体煤柱稳定性提供可靠的判定依据。
[Abstract]:The western mining area has gradually become the focus of coal resources development in China, but the shortage of water resources has become the bottleneck restricting the development of local coal resources. Therefore, comining of coal and water is urgent. At present, the methods of coal and water mining mainly include water conservation and underground reservoir technology, especially the underground reservoir technology has been widely used in Shendong mining area. The stability of underground reservoir is closely related to the stability of artificial dam and coal pillar dam. The instability of coal pillar dam is affected not only by the load but also by the erosion of water. Therefore, it is of great significance to study the shear failure characteristics of coal samples under different water content in order to reveal the deformation characteristics of coal pillar dams in underground reservoirs under the action of water. In this paper, the shear failure strength and characteristic parameters of water-bearing coal samples are systematically studied by compression shear test. By means of acoustic emission and infrared radiation, the shear process of coal samples with different moisture content is inversed and analyzed, and the characteristics of acoustic emission and infrared radiation of coal samples under different water-bearing conditions are obtained, and the model is established. The damage law of water-bearing coal during shear failure is analyzed. The paper starts with the experiment of water absorption and determines five soaking time points. The shear test shows that the shear strength of coal sample decreases gradually with the increase of water content, and the relationship between them is exponential. The shear strength parameters c and 蠁 were analyzed and the results showed that both of them showed a downward trend after soaking, and the Mohr Coulomb failure criterion parameters were modified based on water content. By studying the acoustic emission parameters in shear process, it is found that the characteristics of acoustic emission counting and energy rate are correlated with the change trend of stress-strain curve, that is, with the increase of water content, the characteristics of acoustic emission counting and energy rate are less obvious. Through the analysis of infrared characteristic parameter AIRT in shear process, it is found that with the increase of moisture content, the temperature variation amplitude of AIRT decreases continuously, and the highest and lowest radiation temperatures show the same trend. Combined with the surface radiation temperature entropy and variance, the higher the moisture content, the smaller the surface temperature variance. The global damage variables based on the characteristics of acoustic emission counting and the surface damage variables based on the infrared radiation temperature change point are established. It is found that the whole damage variable is more precursor and stage than the surface damage variable in reflecting the coal sample, while the surface damage variable is more suitable to the stress-time curve at the peak failure stage. Finally, the shear failure damage model of coal sample is evaluated, which provides a reliable basis for studying the stability of dam coal pillar.
【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】：TD821
[Abstract]:The western mining area has gradually become the focus of coal resources development in China, but the shortage of water resources has become the bottleneck restricting the development of local coal resources. Therefore, comining of coal and water is urgent. At present, the methods of coal and water mining mainly include water conservation and underground reservoir technology, especially the underground reservoir technology has been widely used in Shendong mining area. The stability of underground reservoir is closely related to the stability of artificial dam and coal pillar dam. The instability of coal pillar dam is affected not only by the load but also by the erosion of water. Therefore, it is of great significance to study the shear failure characteristics of coal samples under different water content in order to reveal the deformation characteristics of coal pillar dams in underground reservoirs under the action of water. In this paper, the shear failure strength and characteristic parameters of water-bearing coal samples are systematically studied by compression shear test. By means of acoustic emission and infrared radiation, the shear process of coal samples with different moisture content is inversed and analyzed, and the characteristics of acoustic emission and infrared radiation of coal samples under different water-bearing conditions are obtained, and the model is established. The damage law of water-bearing coal during shear failure is analyzed. The paper starts with the experiment of water absorption and determines five soaking time points. The shear test shows that the shear strength of coal sample decreases gradually with the increase of water content, and the relationship between them is exponential. The shear strength parameters c and 蠁 were analyzed and the results showed that both of them showed a downward trend after soaking, and the Mohr Coulomb failure criterion parameters were modified based on water content. By studying the acoustic emission parameters in shear process, it is found that the characteristics of acoustic emission counting and energy rate are correlated with the change trend of stress-strain curve, that is, with the increase of water content, the characteristics of acoustic emission counting and energy rate are less obvious. Through the analysis of infrared characteristic parameter AIRT in shear process, it is found that with the increase of moisture content, the temperature variation amplitude of AIRT decreases continuously, and the highest and lowest radiation temperatures show the same trend. Combined with the surface radiation temperature entropy and variance, the higher the moisture content, the smaller the surface temperature variance. The global damage variables based on the characteristics of acoustic emission counting and the surface damage variables based on the infrared radiation temperature change point are established. It is found that the whole damage variable is more precursor and stage than the surface damage variable in reflecting the coal sample, while the surface damage variable is more suitable to the stress-time curve at the peak failure stage. Finally, the shear failure damage model of coal sample is evaluated, which provides a reliable basis for studying the stability of dam coal pillar.
【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】：TD821
【参考文献】
相关期刊论文 前10条
1 马立强;张W，
本文编号：2362553
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