Characterization of Rock Spatial Modeling and Quick Identification of Unstable Blocks Based on a Digital Photogrammetry

Within a certain domain of rock mass in excavation, identification of all blocks cut by three-dimensional finite random or fixed discontinuities is a critical basic problem in jointed rock mass researches. The deterministic structures of rock mass can be measured by adopting digital photogrammetry measurement technology, which includes three-dimensional structural network simulation, intersecting lines of surface structure, closed-loop analysis and block fast searching. On this basis, analysis of unstable blocks sliding process is realized based on the classical theory of block during rock tunnel construction process. Engineering example analysis and accuracy test results show that this proposed method can identify the complicated block (including the concave form) cut down from numerous structures fast and effectively. Therefore this method shows its strong commonality and reliability, and it can also be used for rock tunnel excavation process advanced prediction and reinforcing scheme optimization.