Local topography and structural features of discontinuities have a great effect on the movement characteristics and failure mechanisms of the unstable rock blocks of the rock slope. By taking full advantage of the geometric information contained in the multi-temporal terrestrial laser scanning (TLS) point clouds, a technique based on a roto-translation method has been developed to track and monitor the movement behavior of blocks in unstable rock slopes. The technique can be completed in three stages: (a) a preliminary change detection is used to distinguish the unstable area by means of a shortest distance (SD) algorithm; (b) an automatic discontinuity identification algorithm is implemented to visually identify the discontinuity sets and to exactly delineate rock blocks in unstable areas; and (c) finally a roto-translation movement monitoring method is applied to track and monitor the unstable rock blocks. This technique permits the user to visually identify the discontinuity sets and to determine their orientation, and therefore provides detailed information of geometric compounding relationships between the slope and joint systems as well as the forming rock blocks which are the key impacts to stability of the rock slope. It permits the user to exactly and visually delineate the rock blocks in the unstable area, and thus the completely tracking and monitoring of lock block movement in unstable rock slopes can be effectively conducted. It overcomes the limited precision of the single TLS points and provides an actual 3D movement measuring method for the blocks rather than a shortest distance. The technique was first used in the movement behavior monitoring of the unstable rock blocks in a post-earthquake high rock slope. The results show that the rock block movement monitoring technique is well suited for providing high-quality data in the assessment of rock failure hazards.

中文翻译：

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利用地面激光扫描对震后高岩坡进行地质调查和不稳定岩块运动监测

不连续面的局部地形和结构特征对岩质边坡不稳定岩块的运动特征和破坏机制有很大影响。通过充分利用多时相地面激光扫描 (TLS) 点云中包含的几何信息，开发了一种基于旋转平移方法的技术来跟踪和监测不稳定岩坡中块体的运动行为。该技术可以分三个阶段完成：（a）通过最短距离（SD）算法使用初步变化检测来区分不稳定区域；(b) 实施自动间断识别算法，以直观地识别间断组并准确描绘不稳定区域中的岩块；(c) 最后应用旋转平移运动监测方法对不稳定岩块进行跟踪和监测。该技术允许用户直观地识别不连续集并确定它们的方向，从而提供边坡和节理系统之间的几何复合关系以及形成岩块的详细信息，这些信息是影响岩坡稳定性的关键. 它使用户能够准确、直观地描绘不稳定区域的岩块，从而可以有效地对不稳定岩坡中的锁块运动进行全面跟踪和监控。它克服了单个 TLS 点的精度有限，并提供了一种实际的 3D 运动测量方法，而不是最短距离。该技术首先应用于震后高岩边坡不稳定岩块的运动行为监测。结果表明，岩块运动监测技术非常适合为岩石破坏危险评估提供高质量数据。