煤系高岭土安全开采理论分析及试验研究

【作者】 夏红兵；

【导师】 沈兆武； 徐颖；

【作者基本信息】 中国科学技术大学 ， 工程力学， 2008， 博士

【摘要】 淮北朔里煤矿富含优质煤系高岭土,采用走向短臂后退式开采,直接跨落法管理顶板。顶板极易冒落,沿空留巷变形大,爆破开采时易崩倒工作面支架,不能满足安全、高效生产的要求。通过相似模拟试验、数值模拟、理论分析和现场观测及分析,研究出了系统的适宜于该矿工作面顶板支护技术、爆破预裂法控制沿空留巷变形技术和高岭土爆破开采技术,探讨了工作面顶板跨落、矿压显现以及沿空留巷顶板围岩破坏规律和减少高岭土爆破震动方法。利用相似材料模型试验得到高岭土开采顶板垮落规律、上覆岩层移动规律、应力分布规律,得到初次来压步距、周期来压步距、工作面超前压力影响范围等参数,为安全高效开采高岭土提供了指导。实测结果表明:相似模拟结果具有较强可信性,能满足生产服务要求;据此改金属摩擦支架为单体液压支架,提高了支架初撑力、稳定性,合理选择了支护密度以及控顶距等参数,确保了顶板稳定,实现了安全开采。针对高岭土开采沿空留巷变形大等特点,提出了沿空留巷顶板预裂爆破技术。数值模拟与实测结果证明,对沿空留巷的顶板实施预裂爆破,工作面前方,沿空留巷的顶底板和两帮变形与无预裂面时相比几乎没有变化;而工作面后方,有预裂面时,顶底板变形明显减小。通过现场观测和分析发现,实施预裂爆破,直接顶板沿预裂面冒落,与无预裂面相比,冒落高度增加、周期来压强度减小并且来压步距也减小。顶板预裂爆破技术能明显减少工作面后方沿空留巷顶板变形。沿空留巷钢围网矸石充填体具有及时提供支护阻力、可适应大变形的能力,并且钢围网可以重复利用,因此钢围网矸石充填可以作为一种巷旁支护形式。针对煤系高岭土爆破震动大且工作面碎石抛掷作用强等问题,通过理论分析,提出了多段毫秒延时爆破技术,优化了起爆方式和顺序,增大了一次爆破规模,降低了爆破作业对顶板和支护设施的损伤,提高了作业安全性。通过本文以上研究,初步建立起高岭土开采顶板支护、预裂爆破法控制沿空留巷变形和高岭土开采控制爆破的理论和技术。提高了高岭土开采的安全性。更多还原

【Abstract】 Huaibei Suli Coal is rich with high quality coal series kaolin. Using trend and short arm dip retreat. Directly span-falling method Control strata. Roof easy caving. Big deform for gob-side entry retaining. Blasting excavation does not meet safety and high efficiency production requirement for easy damaging forest. By similarity simulation experiment and numerical simulation and theoretical analysis and field observation and analysis, obtains comfortable forest roof support technology and blasting control pre-splitting blasting gob-side entry retaining deformation and blasting mining series Kaolin. And probe into Study on forest roof damage and strata pressure and failure law of strata surrounding rock of gob-side entry retaining and decrease blasting vibration to coal series kaolin. The conclusions of the study are as follows.Using simulation experiment with analogy material obtains the roof failure law of coal series Kaolin and moving and stress distribution law of overlying strata. By using numerical simulation, obtains the parameters of first roof pressure and periodic roof pressure and forest leading-pressure and so on. It instructed that safety and high efficiency mine coal series Kaolin. The results showed that analysis result possess credibility by Simulation material model and numerical simulation. And satisfy the effect of produce and service. Change Metal Friction supporter to single-body hydraulic supporter in order that improve the parameters of supporting frame setting load and stability and comfortable select support style and control roof and so on. Make sure roof stability and safety mining.This text puts forward a kind of pre-splitting technique of gob-side entry retaining upper plate, in response to the kaolin clay’s feature of large deformation when exploiting the gob-side entry retaining. According to the numerical simulation and actual measurement we can see: on the anterior of the working face, the deformation of upper plate and the roadway’s sides are almost unconverted in contrast to without splitting face; on the resection of the working face, the deformation of roof and floor has been reduced obviously while taking the pre-splitting blasting on the roof of the gob-side entry retaining. According to on-site observation and theoretical analysis we can get: the caving altitude will increase, the previous roof altitude, the periodic roof pressure and the pace moment of roof pressure will decrease in contrast to without splitting face when taking the pre-splitting blasting. The roof pre-splitting technique has the obvious effect of decreasing the roof deformation of the resection of working face. The steel seine full of dirt pack of periodic roof pressure can provide supporting resistance promptly, and has the capability of adopting large deformation, and the steel seine can use again and again. So the steel seine full of dirt pack can be used as a kind of supporting form of the roadway’s sides.Aiming at great strength of blasting vibration and high rock discharging effect in workplace in mining coal series kaolin .By theoretical analyzing, the blasting mode and sequence were optimized, and blasting efficiency and ore quality of coal series kaolin were markedly raised. Moreover, one blasting scale was augmented, the damnification to roof and supporting was decreased, and the mining safety was enhanced.According to the paper study on: Initial create mining roof support for coal series Kaolin and the mechanics and theory of blasting control pre-splitting blasting gob-side entry retaining deformation and blasting mining series kaolin. Improve mining safety for Kaolin by using this technology.更多还原