修正Q值围岩分级方法在碳酸盐地区大断裂超深埋特长隧道的应用研究

On the Application of a Modified Q-Value Classification to a Long,Deep Tunnel Near Large Faults in a Carbonate Area

在隧道建设过程中,围岩分级的准确性直接关系着隧道施工的稳定性。文章在分析了众多的围岩分级方法以后,选择常用的Q值法作为修正对象;根据碳酸盐地区大断裂超深埋特长隧道的特殊性,提出了以断层、褶皱、地形以及岩溶的宏观影响系数对Q值法进行修正,得出了修正以后的建议Q'值法公式。以大坪山隧道为实例,进行验证分析,得出了在最深埋地段围岩级别较高、离断层最近的围岩级别较差的结论,与实际揭露的围岩级别结果基本一致。

Abstract The slabiliiy of a tunnel depends on the accuracy of the rock mass classification made during the course of its construction. The normal Q value method was modified after analyzing various rock classification methods. Based on the particularities of a long, deep tunnel located at large faults in a carbonate area, the modified Q value method was put forward in respect to the macro influence coefficients of fault, fold, topography, and karst, and the formula for the modified Q value was obtained accordingly. Based on the verification and analysis of the Dapingshan Tunnel, was concluded that the higher the classification of rock mass at great depth, the poorer the rock mass near the faul it t,which means that the formula results are practically idenlical to the actual ones.