深部井巷工程高预应力NPR耦合支护技术

Research of high pre-stress NPR support technology in deep shaft roadway engineering

深部煤炭资源是未来我国能源安全的重要保证,但受深部“三高一复杂”地质力学环境影响,深部井巷工程岩体大变形失稳问题日渐突出。为解决该问题,以支护-围岩相互作用为突破点,研发了具有高强度、高恒阻、大变形力学特性的系列NPR锚杆/索,构建了NPR锚杆的本构方程,并开展室内和现场综合力学试验,验证了NPR锚杆/索的独特力学特性;分析了NPR支护-围岩相互作用关系,推导了NPR支护岩体本构关系,阐明了采用NPR耦合支护后的开挖补偿力学效应,揭示了高预应力NPR耦合支护机理;结合大强煤矿实际工况,提出了深部泵房吸水井以NPR锚杆/索为核心的集约化硐室群NPR支护技术。数值分析和现场监测数据显示:高预应力NPR耦合支护技术可显著提高支护-围岩的承载特性,有效减小井巷工程岩体塑性区的分布及发展范围;支护后支护-围岩应力场趋于均匀化,围岩整体变形量减小68%以上,确保了深部井巷工程岩体的长期稳定。研究成果可为类似条件下的深部井巷工程稳定性控制提供借鉴。

Deep coal resources are the crucial backup for China’s energy security in the future.However,large deformation and instability of rock mass in deep roadway engineering still poses serious problems in the deep“three high and one complex”geomechanical environment.Therefore,this study departed from the support surrounding rock interaction and developed a series of NPR anchor bolts/cables with high strength,high constant resistance and large deformation mechanical properties.It constructed the constitutive equation of NPR anchor bolts,and carried out comprehensive mechanical tests indoor and on-site to verify the unique mechanical properties of NPR anchor bolts/cables.This study analyzed the interaction relationship between NPR support and surrounding rock,derived the constitutive relationship of rock mass supported by NPR,and elucidated the excavation compensation mechanical effect after adopting NPR coupling support,which revealed the high pre-stress NPR coupling support mechanism.By drawing on the actual working conditions of Daqiang Coal Mine,this study proposed the NPR support technology for intensive chambers group of deep pump house suction well with NPR bolt/cable as the core.The numerical analysis and field monitoring data show that the high prestress NPR coupling support technology can significantly improve the bearing characteristics of the support surrounding rock,effectively reduce the distribution and development range of the plastic zone of the rock mass in the roadway engineering,homogenize the support surrounding rock stress field,and reduce the overall deformation of the surrounding rock by more than 68%,ensuring the long-term stability of the rock mass in the deep roadway engineering.The research results can provide reference for stability control of deep roadway engineering under similar conditions.