Terrestrial laser scanner for geophysical hazard mitigation and infrastructure resiliency

需要一台地面激光扫描仪（TLS），以维持和加强地球物理减灾和基础设施复原力方面的土木工程研究。TLS实现了一个自动旋转激光测距仪，每秒测量数十万个点，从中高精度地生成三维（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将用于开发几个前沿研究项目。河流形态动力学的研究将包括在野外对暴露的沙洲表面进行快速扫描，以及在移动河床实验室水槽实验中进行平衡河床测深。比较洪水事件前后收集的dem，可以评估洪水对形态动力学和基础设施的影响。部分饱和土在不同环境条件下的体积变形和运动的基本土力学也将用TLS进行评估。本研究可应用于河岸边坡失稳、溃坝等岩土工程灾害。TLS还将用于绘制大型河谷的形态，以开发3D水流和泥沙运输模型；峡谷壁不能用任何其他方法测量。河流冰盖的生长、固结和衰变也将通过TLS进行调查。由此产生的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评估的唯一自然灾害。将使用TLS对地震和海啸灾后地区进行快速和安全的调查，以评估这些极端载荷对基础设施的影响，从而可以制定改进的建筑规范。基础设施的调查也将应用于生成建筑信息模型（bim），以便在虚拟现实环境（VRE）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测量现有结构（即建筑物，桥梁）的状态，从而能够就维护，维修和更换所需的水平做出决策，以保持基础设施处于可接受的运行状态。

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.