Hurricane Surge and Wave Loads on Near-Coast Structures

菲律宾桑迪、台风海燕等飓风风暴造成灾难性破坏。在近海地区，海浪和巨浪冲击着建筑物和其他建筑物，造成了很大程度的破坏。目前有用于设计的浪涌和波浪荷载的标准。然而，标准经验荷载忽略了非定常波浪和涌浪过程的影响，这可能导致在紧邻海岸线的地方产生更大的荷载。该项目将对这些非稳定结构荷载的性质以及它们如何影响建筑物进行基础性研究。在菲律宾飓风桑迪和超级台风海燕的案例研究的支持下，计算模拟将开发和测试来自非恒定海浪和巨浪的近海岸结构载荷的表示法。结果将使工程师和规划者能够进行更好的设计，因为他们正在努力减少未来飓风造成的损失。在标准的位相平均波浪和涌浪模型中忽略非定常辐射应力，导致低估了近岸区域的最大波高和流速，并忽略了类涌浪载荷。这可能导致对结构设计载荷的严重低估。研究小组将使用Boussinesq和Navier-Stokes流体力学模型研究这些过程，以(1)绘制低频流体动力过程显著的区域图；(2)建立正则几何形状的流体动力特性与相关结构载荷之间的关系；以及(3)出于设计目的综合这些结果。载荷将细分为冲击和准稳定两类，每一类都有不同的分析和综合。比动量通量与载荷成正比的假设将得到严格检验，因为这可能提供一种相对简单的方法，将其中许多过程合并到结构载荷参数中。

Hurricane storms such as Sandy and Typhoon Haiyan in the Philippines have caused catastrophic damage. In the near-coast region, a large amount of this damage has been from wave and surge impacting buildings and other structures. Currently there are criteria for surge and wave loads that are used for design. However, standard empirical loads neglect the effects of unsteady wave and surge processes, which can lead to much larger loads in the immediate vicinity of the shoreline. This project will pursue fundamental research into the nature of these unsteady structural loads, and how they affect buildings. Computational simulation backed up by case studies from Hurricane Sandy and Super Typhoon Haiyan in Philippines will develop and test representations for near-coast structural loading from unsteady waves and surge. Results will allow engineers and planners for better designs as they work to reduce damages from future hurricanes. The neglect of unsteady radiation stresses in standard phase-averaged wave and surge models results in underestimation of maximum wave heights and current velocities in the near-coast region, and the neglect of bore-like loading. This can lead to severe underestimates of structural design loads. The research team will examine these processes using Boussinesq and Navier-Stokes fluid mechanics models to (1) map regions where low-frequency hydrodynamic processes are significant; (2) establish relationships between hydrodynamic properties and associated structural loading for canonical geometries; and (3) synthesize these results for design purposes. Loads will be subdivided into impact and quasi-steady categories, with different analyses and synthesis for each. The hypothesis that specific momentum flux is proportional to loading will be tested closely, as this may provide a relatively simple method to incorporate many of these processes into structural loading parameterizations.