Spatial Variability Effects on the Seismic Response of RC Highway Bridges

该奖项是根据2009年美国复苏和再投资法案(公法第111-5条)资助的。地震引起的地面运动在地球上的任何两个点都不相同--S。这是因为地震波从震源以不同的速度通过不同的路径传播，并通过不同的当地场地条件到达地面。在结构设计中，这种空间变异性常常被忽略。然而，对于空间分布较大的结构，这种地震动的变异性会增加或减少结构的动力响应，具体取决于结构体系的特性。本研究将对影响钢筋混凝土桥梁结构地震反应的系统参数进行全面的研究。调查将包括以下步骤：仔细选择与美国东部、中部和西部有关的记录的地震地面运动；根据记录的数据和运动空间变化的严格模型，在均匀和可变场地条件下产生空间可变的加速度、速度和位移；以及使用产生的输入激励来评估几个典型的钢筋混凝土公路桥的非线性反应。将利用全国各地不同长度的典型桥梁结构，并使用多种计算机/数值模型和工具进行分析，以减少结构数值建模的不确定性。该项目将为评估空间变化的地面运动对桥梁反应的影响提供方法和框架。根据研究结果，提出了在桥梁结构设计和改造中考虑地震运动空间变异性影响的建议，以期更好地了解地震动空间变异性对结构响应的影响。它将确定重要的结构和地面运动参数，对于这些参数，运动的空间变异性将对结构响应产生强烈影响。桥梁设计专业人员将更好地评估空间变异影响，并将其纳入桥梁设计。这最终会增强国家的安全吗？S是至关重要的基础设施。为了更广泛地传播研究结果，以加强更广泛的影响，产生的空间可变地震地面运动和在该项目中开发的结构的数值模型将张贴在一个网站上，供其他研究人员和从事实践的工程师使用。这项工作的成果将通过技术出版物和专题介绍直接传播给业内人士。这项研究还将为研究生和本科生提供高级培训，并纳入K-12科学教师的积极参与。将利用已建立的机构伙伴关系在该项目中招募任职人数不足的群体。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)The earthquake induced ground motions are not the same at any two points on the earth?s surface. This occurs because the seismic waves travel from the earthquake source through different paths with different velocities, and reach the ground surface through different local site conditions. Often this spatial variability is ignored in the design of structures. However, for large spatially distributed structures, this ground motion variability can increase or decrease the dynamic response, depending on the structural system characteristics. This study will conduct a comprehensive investigation to determine what system parameters affect the seismic response of reinforced concrete bridge structures. The investigation will consist of the following steps: a careful selection of recorded seismic ground motions pertinent for the Eastern, Central and Western United States; the generation of spatially variable accelerations, velocities and displacements at uniform and variable site conditions based on the recorded data and rigorous models for the spatial variation of the motions; and the use of the generated input excitations for the evaluation of the nonlinear response of several representative reinforced concrete highway bridges. Typical bridge configurations of various lengths from across the country will be utilized and analyzed using multiple computer/numerical models and tools so as to reduce the uncertainty in the numerical modeling of the structures. The project will provide the methodology and framework for the evaluation of the effect of spatially variable ground motions on the response of bridges. Based on the research results, recommendations for incorporating the effect of spatial variability of seismic motion in the design and retrofit of the bridge structures will be made.The research will lead to a better understanding of the effects of the spatial variability of seismic ground motions on the structural response. It will identify important structural and ground motion parameters for which the spatial variability in the motion will have strong influence on the structural response. The bridge design professionals will be better equipped to evaluate the spatial variability effects and to incorporate them in bridge designs. This will eventually enhance the safety of the nation?s vital infrastructure. For wider dissemination of the research results to enhance the broader impacts, the generated spatially variable seismic ground motions and the numerical models of the structures developed in this project will be posted on a web site for use by both other researchers and practicing engineers. The outcomes of the effort will be directly disseminated to the profession through technical publications and presentations. The research will also provide advanced training to graduate and undergraduate students and incorporate active participation by K-12 science teachers. Underrepresented groups will be recruited in the project using well established institutional partnerships.