Abstract: The combination of structure planes with excavated free surface is likely to form blocks in the underground rock mass project in which some of them usually become unstable blocks. Therefore, how to find out these blocks has significant importance to design and construct an underground project. In this paper a block recognition algorithm based on the analytic geometry of space to rapidly find out rock blocks in underground cavities is suggested and realized by C++ programming. The program BlockSeek, which can be easy to search and visualize two types of block such as tetrahedron and pentahedron, is applied in a project of underground cavities and gets an agreement accuracy with the reality. It shows that BlockSeek can rapidly and accurately recognize blocks of tetrahedron and pentahedron and thus can be considered as a technical tool of rock block recognition for underground cavities.

Key words: block recognition, searching approach, visualization

摘要： 岩体结构面与地下厂房开挖临空面极易构成对工程威胁的不稳定块体，因此如何找出这些块体对工程设计和施工都具有重要意义。在描述结构面空间分布规律的基础上，采用空间解析几何理论，提出了块体快速搜索与识别的方法，并采用C++语言编制了块体识别程序BlockSeek，实现了四面体、五面体两种常见可能滑动块体的快速搜索与识别。通过工程实例的应用并得到了验证。程序具有快速、准确识别四面体、五面体块体的功能，可为地下厂房岩体块体识别及稳定性分析提供良好的技术支持。

关键词: 块体识别, 搜索算法, 可视化