关键词: 深部含水煤样, 高应力逐级加卸载, 张拉破坏, 主控裂隙, 荷载梁

Abstract: The coal mass around deep roadways are often disturbed by mining activities from far to near, while bearing high ground stress loads. As a result, the internal crack damage continues to develop in a stress path similar to the gradual loading and unloading of high stress. If they are still under the influence of water and rock interaction, their bearing capacity will further deteriorate. The water absorption characteristics, wave velocity comparisons, mechanical experimental analyses, and acoustic emission monitoring of deep coal samples from a mine indicate that the deep coal samples containing water exhibit characteristics including rapid water absorption, easy saturation, and overall integrity enhancement after water saturation, and they are mainly characterized by the tensile failure of the open main control crack, which causes the overall failure of the specimen. According to the above characteristics, a loading beam main control crack model is optimized and established herein by combining some factors such as the water content, crack parameters, and system size. The mechanism of the instability characteristics mentioned above deep water-bearing coal samples was elaborated, and the sensitivity analysis and strength verification were conducted. The obtained results were in good agreement with the experimental data, which can serve as a reference for similar experimental research, theoretical modeling, and mining design of fractured coal-rock mass located in deep high stress disturbed water-rich roadways.

Key words: deep coal samples containing water, high stress with gradual loading and unloading path, tension failure, main control crack, loading beam