NEESR Planning/Collaborative Research: Simulation and Design Tools for Tsunami Bridge Engineering

该项目的技术目标是制定海啸荷载和桥梁设计建议，以解决桥梁与建筑物必须区别对待的问题。这些问题包括：(1)三维桥梁几何形状，如桥面形状、斜度和堤防，其水力特性会导致水道化、井眼夹持和屏蔽；(2)在海啸波的初始冲击和外流期间，碎片撞击和碎片筑坝可以大大增加桥梁上的力；(3)对于特殊类型的桥梁和改造策略（如挡泥板的部署或柔性结构的情况）可能具有重要意义的流固耦合效应。还将探讨针对桥梁的改造策略。最近并行处理软件的发展和强大的计算平台的可用性使得模拟这些复杂的效果成为可能。计算流体动力学（CFD）建模将解决三维水力几何形状的影响。物质点法（MPM）将通过对碎片进行明确的建模来解决碎片冲击场和筑坝的影响。在OpenSees中实现的粒子有限元法（PFEM）将允许研究人员考虑流体-结构相互作用、前地震震动的影响和不确定性的影响。作为该计划拨款的一部分，将充分开发模拟策略，以指导2015财年早期NEES2设施中关键实验的详细设计。在过去的十年里，海啸造成了数十万人死亡和数千亿美元的损失。关键生命线结构的丧失，推迟了应急工作和灾后经济复苏，加剧了这些灾难。大型海啸还威胁着美国至少五个州和许多美国领土。过去几乎所有的海啸研究都集中在助跑模型、疏散策略的发展，以及最近的抗海啸建筑设计上。相比之下，很少有研究涉及桥梁的海啸性能，也没有指导方针来设计安全和经济的抗海啸桥梁或制定改造策略。为了达到这些目的，所提出的研究将改变抗海啸桥梁的设计，从而大大提高灾后反应和恢复工作。该项目的数据将存档，并通过NEES数据储存库向公众提供。该奖项是国家减少地震灾害计划（NEHRP）的一部分。

The technical objective of this project is to develop tsunami loading and design recommendations for bridges that address issues that must be treated differently for bridges than for buildings. These issues include (1) three-dimensional bridge geometries such as deck shape, skew and embankments, whose hydraulic characteristics can lead to channelization, bore entrapment, and shielding; (2) debris impact and debris damming that can greatly increase the forces on a bridge, both during the initial impact of the tsunami waves and during the outflows; and (3) fluid-structure interaction effects that can be significant for particular types of bridges and retrofit strategies, such as the deployment of fenders or in cases with flexible structures. Bridge-specific retrofit strategies will also be explored. Recent advances in the development of parallel processing software and the availability of powerful computational platforms make it possible to simulate these complex effects. Computational fluid dynamics (CFD) modeling will address the effects of three-dimensional hydraulic geometries. The Material Point Method (MPM) will address the effects of debris impact fields and damming by modeling debris explicitly. The Particle Finite Element Method (PFEM), as implemented in OpenSees, will allow researchers to consider the fluid-structure interaction, the effects of the preceding earthquake shaking and the effect of uncertainties. As part of this planning grant, the simulation strategies will be developed sufficiently to guide the detailed design of critical experiments in a NEES2 facility early in FY2015. Over the past decade, tsunamis have caused hundreds of thousands of deaths and hundreds of billions of dollars of damage. The loss of critical lifeline structures has exacerbated these catastrophes by delaying emergency response efforts and post-event economic recovery. Large tsunamis also threaten at least five U.S. states and numerous U.S. territories. Nearly all past tsunami research has focused on run-up modeling, the development of evacuation strategies, and more recently, on the design of buildings to resist tsunamis. In comparison, little research has addressed the tsunami performance of bridges, and no guidelines are available to design safe and economical tsunami-resistant bridges or to develop retrofit strategies. To these ends, the proposed research will transform the design of tsunami-resistant bridges, and consequently, greatly improve post-event response and recovery efforts. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).