RAPID/Collaborative Research: Geotechnical and Geoenvironmental Properties of the Ahr Valley and Their Role in Structural Damage During Recent Flooding

这项快速反应研究赠款(RAPID)奖将侧重于收集和处理关于2021年西欧洪水期间受影响的基础设施和河段附近侵蚀和沉积模式的空间分布的高分辨率、易腐烂的数据。这些数据将被询问，以深入了解渠道几何形状、水流条件、碎石的存在和岩土特性如何影响与极端洪水相互作用的工程结构的性能。这在全球气候变化的背景下是相关的，预计极端洪灾将更频繁和更大规模地发生。许多在德国洪水中受损的现代建筑与美国各地发现的建筑相似，从这次洪水事件中获得的知识将被转移到美国的建筑环境中。项目期间产生的数据可以为更新基础设施设计和洪水缓解策略提供支持，以满足未来因气候变化而加剧的需求。本研究的具体目标是提供有关极端洪水事件对基础设施的影响以及城市土地使用和环境条件的影响的新数据和知识。通过这种数据收集，一套详细的案例研究记录了基础设施附近和城市河段的沉积物动力学，将有助于确定在极端洪水期间可能影响工程结构性能的特征和过程。河床内的地球物理场测量将包括旋转侧扫声纳、高分辨率线性调频声纳和单波束声纳。这将使收集航道水深和沉积物地层学成为可能，这可能揭示有关河床上部米底质的变化是否或如何在极端水力事件期间对泥沙动员和不稳定起重要作用的新信息。地面和机载激光雷达测量都将提供河岸和周围结构的高分辨率3D模型，从而能够评估侵蚀模式和结构破坏之间的潜在相互作用。将使用基于无人机的技术收集多光谱图像，以识别更广泛的侵蚀和沉积模式。岩土现场测量将包括袖珍自由落体渗透仪、袖珍侵蚀仪、野外叶片剪切和野外落锥测量，以及为实验室测量收集的样本。岩土观测，加上地球物理和遥感数据，将能够全面评估沉积物是如何在工程结构附近被侵蚀和运输的。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant for Rapid Response Research (RAPID) award will focus on collecting and processing high resolution, perishable data on the spatial distribution of erosive and depositional patterns in the vicinity of infrastructure and river sections that were affected during the 2021 Western European Floods. These data will be interrogated to provide insight into how channel geometry, flow conditions, the presence of debris, and geotechnical properties affect performance of engineered structures interacting with extreme floods. This is relevant in the context of global climate change where extreme flooding is expected to occur more frequently and at larger magnitudes. Many of the modern structures that were damaged during the flooding in Germany are similar to structures found across the United States and knowledge gained from studying this flooding event will be transferable to the built environment in the United States. Data generated during the project can provide support to update infrastructure design and flood mitigation strategies to meet future demands intensified by climate change.The specific goal of this research is to provide new data and knowledge on the impact of extreme flooding events on infrastructure and the effects of urban land usage and environmental conditions. Through this data collection, a detailed set of case studies that document sediment dynamics in the vicinity of infrastructure and in urban river sections will facilitate identification of features and processes that potentially influence performance of engineered structures during extreme flooding. Geophysical field measurements in the riverbed will include rotary side scan sonar, high resolution chirp sonar, and single beam sonar. This will enable collection of channel bathymetry and sediment stratigraphy, which may reveal novel information on if or how changes in substrata in the upper meter of the river bed play a significant role in sediment mobilization and instability during extreme hydraulic events. Both ground-based and airborne LiDAR surveys will provide high-resolution, 3D models of the riverbanks and surrounding structures, enabling assessment of potential interaction between erosive patterns and structural damage. Multispectral images will be collected using drone-based technology to identify broader erosive and depositional patterns. Geotechnical field measurements will include pocket free fall penetrometer, pocket erodometer, field vane shear, and field fall cone measurements in addition to sample collection for laboratory measurements. The geotechnical observations, coupled with the geophysical and remote sensing data, will enable a comprehensive assessment of how sediments were eroded and transported near engineered structures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.