多次采掘扰动下小煤柱失稳特征及控制技术研究

Research on Instability Characteristics and Control Technology of Small Coal Pillars under Multiple Mining Disturbances

以某矿7 m小煤柱为研究对象,通过理论分析、相似材料模拟、数值模拟和现场实测等方法发现,一次掘进扰动后,煤柱破坏区宽度为2 m,二次掘进扰动后,煤柱破坏区宽度为2.2 m,一次回采扰动后,煤柱基本已发生完全破坏,二次回采扰动后,破坏程度进一步加剧,提出基于“树形骨架结构”围岩改性的区段小煤柱稳定性控制技术,通过现场试验发现,围岩改性后,顶底板移近量从60 mm/月降低至24 mm/月,且围岩完整性有明显提高,证明可以有效提高小煤柱稳定性。

Taking a 7 m small coal pillar in a mine as the research object,it was found through theoretical analysis,similar material simulation,numerical simulation,and on-site measurement that after the first excavation disturbance,the width of the coal pillar failure zone was 2 m,and after a second excavation disturbance,the width of the coal pillar failure zone was 2.2 m.After the first mining disturbance,the coal pillar had basically been completely damaged.After a second mining disturbance,the degree of damage further intensified.A section small coal pillar stability control technology based on the"tree shaped skeleton structure"surrounding rock modification was proposed.Through on-site experiments,it was found that before and after the surrounding rock modification,the displacement of the top and bottom plates decreased from 60 mm per month to 24 mm per month,and the integrity of the surrounding rock was significantly improved,proving that the stability of the small coal pillar can be effectively improved.