为了解决隧道工程施工中围岩稳定性分析这一工程难题，依托某在建公路隧道，基于地质素描与数理统计分析工作，精细化描述节理产状、间距、填充物、黏聚力等特征，并利用三维重构技术建立基于节理特征的隧址区地层模型，最后利用块体理论检索了无支护、有支护工况下隧道临空面潜在的关键块体，分析了滑移形式和安全系数，并对支护参数进行了优化，得知原设计支护强度富余，适当优化后仍可确保结构安全。

The occurrence, spacing, filler, cohesive force and other characteristics of the joints of the surrounding rock of a highway tunnel under construction are described in detail on basis of geological sketches and mathematical statistics work, so as to solve the problems in the analysis on the stability of the surrounding rocks in tunnel construction. Then the model of the strata in the tunnel site, which is based on the joint properties, is established by means of threedimensional reconstruction technology. Finally, the potential critical blocks in the free face under nonsupport condition and under support condition are examined by means of block theory, the slip mode and the safety factor are analyzed, and the supporting parameters are optimized. It is concluded that the strength of the designed support is higher than needed and that the safety of the structure can also be guaranteed when the supporting parameters are appropriately optimized. 