Safety Branch, China Coal Research Institute National Key Lab of Coal Resource High Efficient Mining and Clean
Uillization School of Safety Engineering, China University of Mining & Technology

为了分析实施水力割缝、冲孔等水力化卸压增透技术后的煤层在煤巷掘进中发生的煤壁片帮、打钻卡钻等问题,采用物理相似模拟结合颗粒流软件PFC数值模拟的方法,模拟分析了围压条件下切槽煤层内部应力、裂隙的动态演化过程,探讨了煤层切槽后的损伤破坏特征。结果表明:煤层内有多个切槽分布时,相邻切槽端出现应力集中且煤体损伤发育,而切槽面上下侧煤体的卸压作用显著;随着切槽厚度的增大,切槽面卸压效果增强,煤体易损伤变形,孔隙率随之显著增大。煤层内切槽会增强煤体应力场和裂隙场的不均一性,切槽端和边界处应力集中使煤体不稳定,设计合理的切槽尺寸是降低煤巷打钻与巷道维护难度的有效方法。

In order to analyze the coal wall spalling, dilling bit jammed and other problems occurred in the seam gateway driving in the seam after the hydraulic sIo tting, punching and other hydraulic pressure releasing and permeability improved technology conducted, a physical similarity simulation combined with a particle flow so ftware PFC numerical simulation method was applied to simulate and analyze the internal stress and crack dynamic evolution process of the slotted seam under the sur rounding pressure condition and to discuss the damage and failure features after the seam slotted. The results showed that when several slots made in the seam, a stre ss concentration would be occurred at the end of the adjacent slot and the damage development would occurred in the seam. Thus the pressure released role of the se am at the top and bottom of the slotting profile would be obvious. With the thickness of the slot increased, the pressure released effect of the slot profile would be incre ased, the seam would be damaged and deformed easily and the porosity would be obviously increased. The slotting within the seam would strengthen the uneven of the seam stress field and the crack field, the stress at the slot end and boundary would remarkably increase the unstability of the seam and the designed rational slot size would be an effective method to reduce the drilling difficulty of the seam gateway and the maintenance difficultyt of the gateway.

国家重点基础研究发展计划(973计划)资助项目(2011CB201206)；国家科技重大专项资助项目(2011ZX05040-001,2011ZX05063-009)；国家自然科学基金青年基金资助项目(51444006)；