Terrestrial laser scanner for geophysical hazard mitigation and infrastructure resiliency

需要地面激光扫描仪(TLS)来支持和加强在地球物理减灾和基础设施复原力方面的土木工程研究。TLS实现了每秒数十万个点的自动旋转激光测距仪，从中可以高精度地生成三维(3D)点云，从而生成自然和/或建筑环境的3D数字高程模型(DEM)。拟议的TLS将用于开发几个尖端研究项目。河流地貌动力学的研究将包括野外裸露沙洲表面的快速扫描和移动床实验室水槽实验中的平衡床水深测量。通过比较洪水事件前后收集的数字高程模型，可以评估洪水对地貌、动力和基础设施的影响。由于环境条件的变化，部分饱和土壤的体积变形和运动的基本土力学也将用TLS进行评估。这项研究适用于河岸、堤坝决口和其他岩土灾害中的斜坡破坏。TLS还将用于绘制大型河流峡谷的地貌图，以开发3D水流和泥沙传输模型；峡谷壁不能通过任何其他方法进行测量。TLS还将调查河流冰盖的增长、巩固和衰退。所得数据将用于验证新开发的冰盖动态摄影测量分析算法，包括与灾难性洪水有关的冰塞的形成。河流洪水并不是TLS将评估的唯一自然灾害。地震和海啸灾后地区将使用TLS进行快速和安全的调查，以评估这些极端荷载对基础设施的影响，从而可以制定改进的建筑规范。基础设施调查还将用于生成建筑信息模型，以便在虚拟现实环境中查看。这将包括使用TLS调查的裂缝发展的详细分析，使我们的研究团队能够衡量现有结构(即建筑物；桥梁)的状态，从而能够就保持基础设施处于可接受的运行状态所需的维护、维修和更换水平做出决策。

A terrestrial laser scanner (TLS) is requested to sustain and enhance civil engineering research in geophysical hazard mitigation and infrastructure resiliency. A TLS implements an automatically rotating laser range-finder to survey hundreds of thousands of points per second, from which a three dimensional (3D) point cloud is generated with high accuracy, leading to a 3D digital elevation model (DEM) of a natural and/or built environment. The proposed TLS will be used to develop several cutting-edge research projects. Studies of river morphodynamics will involve rapid scanning of exposed bar surfaces in the field and equilibrium bed bathymetry in mobile-bed laboratory flume experiments. Comparison of DEMs collected before and after flood events will permit evaluation of the morphodynamic and infrastructure impacts of flooding. The fundamental soil mechanics of volumetric deformation and movement of partially saturated soils due to varying environmental conditions will also be assessed with the TLS. This research has application to slope failures in river banks, dams breaching, and other geotechnical hazards. The TLS will also be used to map morphology of large river canyons for development of 3D flow and sediment transport models; canyon walls cannot be surveyed by any other means. Growth, consolidation, and decay of river ice covers will also be surveyed with the TLS. The resulting data will be used to validate newly developed algorithms for photogrammetric analysis of ice cover dynamics, including formation of ice jams linked to catastrophic flooding. River floods are not the only natural hazards that will be assessed with the TLS. Earthquake and tsunami post-disaster zones will be rapidly and safely surveyed using the TLS to evaluate the impacts on infrastructure due to these extreme loads, from which improved building codes can be developed. The survey of infrastructure will also be applied for generation of Building Information Models (BIMs) for view in a Virtual Reality Environment (VRE). This will include detailed analysis of crack development as surveyed using the TLS, enabling our research team to measure the status of existing structures (i.e., buildings; bridges), enabling decision-making regarding the level of maintenance, repair and replacement required to keep the infrastructure in acceptable operational conditions.