摘要
针对深埋硬岩隧道围岩变形及地质灾害等问题,文章基于分形理论的计算方法,对锦屏二级水电站深埋引水隧洞施工过程中的围岩变形量进行了分形特征研究。结果表明:深部岩体隧洞开挖施工过程中,围岩的形变在时间上是具有分形特征的,而且呈现出较好的自相似结构特征;在同一埋深的条件下,分形维数最大值在隧洞拱顶部,其次在拱肩,边墙分形维数最小;埋深在500~1 800 m外,围岩灾害发生的频率同样随隧洞深度增加而明显呈现出增长的趋势;但当隧洞埋深在1 800 m范围之外时,变形量分形维数及围岩灾害发生的频率趋于稳定,受到埋深的影响很小。
As for the rock mass deformation and geological hazards of deep-buried hard rock tunnels,based on the calculation method of the fractural theory,it studied the fractal features of rock mass deformations during the construction of deep-buried water conveyance tunnels of Jinping II hydropower station.The results show that it has the temporal fractal characteristics for the deformation of surrounding rocks during the construction of deep rock tunnels,and it exhibits good self-similarity structural features;under the same buried depth,the maximum fractal dimensions occur at the tunnel crown,then it decreases at spandrel,and the minimum fractal dimensions occur at the side wall;as for the tunnel with buried depth of 500-1 800 m,the larger the buried depth is,the larger the increase of deformation fractal dimensions and the occurrence frequency of surrounding rock hazards;as for the tunnel with buried depth more than 1 800 m,the deformation fractal dimensions and the occurrence frequency of surrounding rock hazard tend to be stable and the buried depth has a little effect on it.
引文
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