高压水载荷下煤体裂缝的起裂判据及延展规律.PDF

33 7 2014 7 Vol.33 No.7 Journal of Liaoning Technical UniversityNatural Science Jul. 2014 1008-0562(2014)07-0892-06 doi:10.3969/j.issn.1008-0562.2014.07.006 高压水载荷下煤体裂缝的起裂判据及延展规律 1,2 1 2 （1.中国矿业大学 （北京）资源与安全工程学院，北京 100083 ；2.河南工程学院 安全工程学院，河南 郑州 451191 ） 为对水力压裂煤体裂缝的起裂判据作定量计算，根据弹性力学理论，分析了注水钻孔周围的应力状态， 给出了水平和垂直裂缝产生时注水压力的计算模型；探讨了裂缝扩展的方向以及其扩展所需要的泵注压力；采用 自制的高水载荷下煤体裂隙生成及延展模拟装置在实验室模拟了不同围压和轴压加载下条件下煤体起裂的临界 注水压力及裂隙生成和延展的方向.实验研究表明：泵注压力克服最小主应力与煤体的抗拉强度之和时，煤体开 始破裂；裂隙总是沿着最大主应力的方向发展.实验模拟结果和理论分析相吻合. 裂缝起裂；延展规律；试验装置；水力压裂；泵注压力 TD712.1 A Crack fracture criterion and extension regularity about coal loaded by high pressure water 1,2 1 2 TIAN Kunyun , GUO Deyong , ZHANG Ruilin (1. School of Resoure and Safty Engineering, China University of Mining and Technology(Beijing), Beijing 100083, China; 2.Department of Safty Science ＆Engineering, Henan Institute of Engineering, Zhengzhou 451191, China) Abstract: The stress state around water injection hole was analyzed and the crack fracture criterion was calculated according to the theory of elastic mechanics quantitatively. The calculation model about water injection pressure is given when horizontal and vertical cracks appear. The direction of crack propagation and its required pressure is explored. In the laboratory, the critical injection pressure and the direction of crack generation and extention is simulated employing the self-developed simulation device about coal crack generation and extention loaded by the high pressur