Coal Mining Branch, China Coal Research Institute Coal Mining & Designing Department, Tiandi Science &
Technology Co., Ltd.

为改善含厚硬夹矸难冒顶煤的冒放性,以芦子沟煤矿合层开采的巨厚煤层作为工程研究背景,基于弹性力学理论研究硬厚夹矸层的力学结构,得出了厚硬夹矸层"短悬臂梁"结构发生拉断失稳和剪切破断失稳条件下的判据公式,作为确定架间定向水力压裂致裂夹矸层分段切槽的依据。同时结合KZ54型开槽钻钻头特征,将夹矸层分段致裂长度定为0.8 m。研究结果表明:水力压裂水压曲线波动变化不大,表明裂缝持续向前扩展;致裂后煤矸块度减小,顶煤体顺利放出;3107工作面上端头顶煤致裂后支架工作阻力增加;架间定向水力压裂技术有利于改善顶煤冒放性。

In order to improve caving and drawing characteristics of extremely thick coal seam with dirt band, authors studied the mechanical structure of hard and thick dirt band with elastic mechanics theory, based on commingled production engineering of extremely thick coal seam at Luzigou Mine. The“short cantilever' 'structur e formulas of hard and thick dirt band were obtained, when the structure occurred tensile failure and shear localization. They were the main basis of piecewise slotting, when directional hydraulic fracturing between supports was used to crack dirt band. The fracturing piecewise length was determined as 0.8 m, in view of the KZ54 Type slotting drill features. The study results showed that the fracturing pressure curves fluctuated lttlet, which showed that cracks continued to expand forward; after fracturi ng, blocks of dirt band and coal were decreased, and top coal were out smoothly; working resistance of supports increased at the upper end of the No. 3107 face after f racturing. Directional hydraulic fracturing between supports helps to improve top coal caving.

国家自然科学基金青年基金资助项目(51504135)；煤炭科学研究总院科技创新基金资助项目(2015ZYJ001)；天地科技股份有限公司技术创新基金资助项目(KJ-2015-TDKC-02)；