开挖空间模型构建和不稳块体识别是岩体稳定性研究中非常重要的基础性研究课题。采用数字摄像测量技术可快速获取现场围岩结构面信息,建立围岩开挖空间模型。在此基础上,提出一种新的块体识别方法,即将岩体划分为小的块体单元,然后依次添加结构面,对块体单元进行切割,最后去除网格合并块体单元形成形态复杂的空间块体模型。运用该识别方法对丹东-大连高速公路隧道工程的不稳块体进行快速识别,结果显示:该方法具有较强的通用性和可靠性,有助于岩体隧洞开挖过程中超前预报和加固方案的优化。
The 3D modelling and the identification of unstable blocks are the crucially basic issues in jointed rock mass stability research. The deterministic structures of rock mass can be measured by adopting digital photogrammetry, and the model can be built by 3D structural network simulation, intersecting lines of surface structure and closed-loop analysis. A new block identification method is proposed: rock mass is divided into mesh and small block units are formed, then structure surfaces are added orderly to cut block into small units, after that mesh is removed and small block units are merged, finally a complex block is formed. An engineering example is analyzed based on this new identification method. The results show that the method is possessed of preferable generality and reliability, and it also could be used for advanced prediction and reinforcing scheme optimization in excavation process of rock tunnel.