摘要
应用计算机数值模拟结合现场实测,对软岩、中硬岩和硬岩采场围岩应力壳力学特征的岩性效应进行了分析和研究。研究表明:岩性变化对应力壳力学特征有显著影响,随岩性增强,应力壳高度降低,且由拱形壳向扁平壳转变;壳体内最大应力峰值和高应力集中范围逐渐增大并向工作面上隅角近场围岩和煤柱逼近,冲击性失稳的动力灾害危险性增大。岩性不同,工作面围岩的主要承载力系亦不同,软岩工作面最主要承载力系是围岩应力壳;中硬岩工作面,上覆岩层荷载由围岩应力壳和基本顶承载岩层共同承担;硬岩工作面,围岩应力壳与基本顶承载岩层重合在一起。随岩性增强,工作面围岩破坏场、位移场的分布范围和强度均减小。因此,根据工作面围岩固有的力学属性采取相应的措施,通过改善采场围岩应力分布,对缓和矿压显现实现安全开采有积极作用。
The mechanical characteristics of mining-induced stress shell （MISS） in soft rock, medium hard rock and hard rock respectively, were studied through numerical simulation and field measurement. Results show that lithology has significant effect on the mechanical characteristics of MISS. The shape of MISS changes from arch shell to fiat shell with decrease in rock strength, and the height of MISS decreases with lithology enhancing. The stress peak and area of high stress concentration increase and approaches near-field surrounding rock and coal pillars of the upper comer as li- thology enhances, indicating that the potential of dynamic instability increases. The primary supporting body of rock surrounding face is different with lithology. The primary supporting body is MISS in soft rock, MISS and basic roof in medium rock. MISS is together with bearing strata of basic roof in hard rock. The failure and displacement field decreases as lithology enhances. Given the mechanical characteristics of surrounding rock, it is possible to take corresponding measures to improve stress distribution and to mitigate ground pressure for safe mining.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2013年第1期44-49,共6页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2010CB226806)
国家自然科学基金资助项目(51174003
51104004)
关键词
应力壳
岩性效应
采场围岩
力学特征
mining-induced stress shell
lithologie effect
surrounding rock
mechanical characteristic
