立井破碎基岩段围岩强度及支护等级划分标准

Classification standard of strength and supporting level for surrounding rock in shaft broken bedrock section

立井过破碎基岩段施工过程中常常发生围岩的突然垮塌,造成人员伤亡事故.通过分析现有技术存在的问题,有必要提出一套操作性好、可定量的围岩强度及支护等级划分标准.综合考虑岩体基本质量指标、RQD值、岩石软化系数等因素,有针对性的对立井破碎基岩段进行了围岩强度等级再划分;通过不同围岩强度等级、不同开挖直径和不同深度的井筒破碎段围岩稳定性数值模拟,并提取其位移关键值,利用围岩失稳的位移判据,提出了一套针对立井破碎基岩段围岩支护等级划分标准;结合现有立井施工支护技术,形成以不同支护等级为依据的立井破碎基岩段围岩稳定控制技术.通过阳煤集团景福煤矿副立井过破碎基岩段的实际应用,验证了该技术的科学性、合理性、有效性.

The surrounding rock often collapse suddenly in the construction of vertical shaft through fractured rock,causing casualties accidents.Classification standard of rock strength and supporting level,which is operationally and can be quantitated,should be proposed necessarily by analyzing the problems of existing technology.Taking into account basic quality indicators of rock mass,RQD value and softening coefficient of rock,the strength grade of surrounding rock was classified.The stability of broken surrounding rock was numerically simulated through different strength of surrounding rock,different excavation diameter and different depth shaft, and the critical values of displacement were picked up and analyzed. Using rock failure displacement criterion,the standard of supporting grade was classified for broken surrounding rock in vertical shaft.Combined with current support technology in shaft construction,the technology of stability control for corresponding fractured rock was formed on the basis of different supporting level in vertical shaft. The technology is actually used for vice shaft through fractured rock in Jingfu coal mine,and proved scientifically, reasonably and effectively.