综合运用现场实测、数值模拟与工程实践等手段,分析了磴槽煤矿下伏煤层开采软岩巷道围岩的变形破坏特点,揭示了下伏开采软岩巷道底鼓机理:下伏煤层采动使巷道底板成为碎裂结构,并致使巷道两帮产生收敛变形挤压底板;破碎的巷道底板在地应力和集中应力共同作用下向巷道内移动,形成底鼓.提出了由预留变形量、初次高性能锚网喷支护、锚注二次加固、底角高性能锚固与注浆加固组成的底鼓控制技术.工程应用效果表明,所提出的底鼓控制技术有效地控制了巷道底鼓,保证了巷道围岩和支护结构的稳定,可为其他下伏开采软岩巷道的支护设计与底鼓控制提供理论依据和实践参考.%In this paper,analysis was made on the deformation and failure characteristics of the surrounding rock of the soft roadway in the mining of underlying coal seam in Dengcao Mine by means of field measurement,numerical simulation and engineering practice,and based on this,the floor heave mechanism of the soft roadway were revealed:the floor stratas became extremely cracked due to the mining of underlying coal seam;the broken roadway floor moved towards the roadway under the combined action of the concentrated stress and strata stress,which caused the formation of floor heave.For this purpose,a control technology with the combination of reserving deformation,bolt-net-anchor-shotcrete support,bolt-grouting consolidation,bottom angle anchorage and consolidation by grouting was proposed.The effect of engineering application showed that the proposed control technology could effectively control the floor heave and deformation of the roadway and guarantee the stability of the surrounding rock and support structure of the roadway,so it can provide some theoretical basis and practical reference for support design and floor heave control of other soft roadways with underlying seam mining.
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