地下洞室分步开挖围岩应力变化特征及岩爆预测.pdf

第 32 卷增刊 2 岩 土 力 学 Vol.32 Supp.2 2011 年 8 月 Rock and Soil Mechanics Aug. 2011 文章编号：1000－7598 (2011)增刊 2 －0430 －07 地下洞室分步开挖围岩应力变化特征及岩爆预测 邱道宏，张乐文，薛翊国，苏茂鑫 （山东大学岩土与结构工程研究中心，济南 250061 ） 摘 要：为分析大型地下洞室分步开挖各开挖层之间的应力相互影响情况及利用先开挖层的岩爆发生情况来预测后开挖层的 岩爆情况，采用数值计算和现场监控测量的方法进行了一系列计算分析。结果表明：当初始应力场中水平应力和竖向应力相 当时，随着不断地开挖进尺，拱顶、底角和底板的应力先期增加明显，后期增幅变小，逐渐稳定。先开挖层若发生岩爆，后 开挖层底角和底板也会出现岩爆，洞室先期开挖岩爆的风险较大，后期较小。当初始应力场中水平应力占主导地位时，随着 不断地开挖进尺，拱顶、底角和底板的应力先期增幅不大，后期变化较快，侧压力系数越大，先开挖层若发生岩爆，后开挖 层在后期开挖时出现岩爆的风险也越大。最后通过洞室的实际开挖情况验证了分析结果的正确性，利用各层之间的相互影响 特征来预测后开挖层的变形破坏情况为地下洞室稳定性分析提供了一种新的思路。 关 键 词：地下洞室；分步开挖；岩爆；侧压力系数；数值分析 中图分类号：TU 452 文献标识码：A Studies of surrounding rock stress change character and rockburst prediction of underground cavern during stepped excavation QIU Dao-hong, ZHANG Le-wen, XUE Yi-guo, SU Mao-xin （Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan 250061, China ） Abstract: In order to analyze the mutual influence of different layers stresses in the progress of every excavation step and take advantage of the former rock burst situation to predict the rock burst intensity of later layer, numerical calculation and in-site supervision measure are adopted to conduct a series of calculations and analysis. The results show as follows. When horizontal stress and vertical stresses of the initial stress field are equal, the stresses of vault, corner and the floor increase significantly at early period, and smaller increase later, gradually stabilized with the excavation progress. If the former layer rock burst appears, the vault, corner and floor of the later layer rock burs