1. Faculty of Resource and Safety Engineering,China University of Mining and Technology ( Beijing),Beijing　 100083,China;2. The National Coal Mine Water Disaster Prevention and Control Engineering Technology Research Center (Beijing),Beijing　 100083,China

针对厚松散含水层、薄基岩等特殊地质条件下楔形区工作面防砂安全煤岩柱失稳溃砂的问题,以赵固一矿11071工作面突水溃砂灾害为例,结合地质钻孔资料,建立了楔形保水压采动溃砂地质模型。通过黏土液塑限试验,风化带岩石干燥饱和吸水率和崩解试验,得出了底黏及风化带泥类岩具有良好的隔水性能,可形成楔形保水压结构。并在此基础上,通过水压作用下风化带泥类岩采动裂隙扩展试验研究了受采动损伤的煤岩柱保护层在水压作用下失稳的内在致灾机理。结果表明:在高水压的作用下,风化带泥类岩采动裂隙扩展为管道,防砂煤岩柱保护层的阻砂性能失效;考虑煤岩柱保护层的损伤厚度,提出了水压作用下防砂安全煤岩柱的留设方法,并在11191工作面进行了工程应用,取得了预期效果。研究成果补充完善了我国防砂安全煤岩柱的留设方法,可减少煤矿溃砂事故。

In terms of the problems of instability and sand inrush of coal and rock pillar in working face of wedge area under special geological conditions,such as thick loose aquifer,thin bedrock,and so on,taking the water inrush and sand inrush disaster from No. 11071 working face of Zhaogu No. 1 Coal Mine as an example,combined with geological drilling data,a geological model of wedge shape preserving water pressure mining-sand inrush is established. Through clay liquid plastic limit test,dried and saturated water absorption and disintegration test,it is concluded that bottom clay and weathered mudstone has a good water-proof performance,and can form a “wedge protect pressure” structure. On this basis,through the experiment of weathered mudstone mining crack extension under water pressure,the inherent disaster-causing mechanism of instability of coal and rock pillars of sand layer that is affected by mining damage under water pressure is studied. The results show that under a high water pressure,the mined crack in weathered mudstone extends to pipeline,thus the sand-proof properties of the protective layer fail. Considering the damage thickness of weathered zone of coal pillar,the method of setting up the sand-prevention safety coal and rock pillar under water pres- sure was put forward,and an engineering application was carried out in No. 11191 working face and achieved the ex- pected results. Research results complement the design method of sand prevention safety coal and rock pillars in China,and can reduce the coal mine collapse sand disasters and accidents.

国家重点基础研究发展计划(973)资助项目(2013CB227903)；国家自然科学基金煤炭联合基金重点资助项目(U1361209)；

Xu Yanchun,Du Mingze,Li Jianghua,et al. Instability mechanism and design method of coal and rock pillar under water pressure[ J]. Journal of China Coal Society,2017,42(2):328-334.