NEESR-SG: Seismic Simulation and Design of Bridge Columns under Combined Actions, and Implications on System Response

David Sanders，内华达大学，Reno，PIAbdeldjelil DJ Belarbi，密苏里大学，Rolla，Co-PIShirley Dyke，华盛顿大学，Co-PIAmr Elnashai，伊利诺伊大学，Urbana-Champaign，Co-PIJian Zhang，加州大学洛杉矶分校，Co-PiJian Zhang，由空间复杂的地震地面运动、结构配置特征以及输入和反应特征之间的相互作用引起的联合作用和变形。荷载联合作用会对钢筋混凝土柱的受力和变形能力产生显著影响，导致意外的大变形和广泛的破坏，进而影响作为交通系统重要组成部分的桥梁的性能。在桥梁的地震分析和设计中应考虑这些影响，以减少严重的地震破坏和对交通系统的严重干扰。该项目的目标是了解联合行动对色谱柱性能和系统响应的影响的基本知识，并建立分析和设计程序，其中包括组件和系统两级的影响。这些目标将通过将分析和实验研究相结合来实现，其中物理测试由分析和模拟来驱动，这些分析和模拟检查不同类型桥梁在不同荷载条件下的系统响应。利用实验数据对分析模型进行了标定，并将其推广到系统响应。该实验计划包括在密苏里大学罗拉分校(UMR)对24根大柱进行准静态测试(14根将由NEES资助)，提供包括扭矩影响的基本性能测试；在伊利诺伊大学厄巴纳-香槟分校(UIUC)的桥梁系统模拟内对三根具有可变轴向载荷的三根大型柱和四根小型柱进行伪动态测试；在内华达大学雷诺(UNR)对具有双向、扭转和可变轴向载荷输入的八根大型柱进行实时动态测试；由墨西哥大学(UNAM)提供的四项测试；以及通过模拟连接的三根柱的综合试验，由UMR在UIUC进行。将进行易损性分析，从而推导出桥梁在联合作用下基于概率的易损性关系。将开发简化的分析和设计工具以及必要的代码语言，以改变现有做法。设计和分析方法将对美国和国际上的抗震设计实践产生影响。美国和日本的研究人员已经开始协调一个综合测试计划。分析部分将在加州大学洛杉矶分校、UIUC、UMR和UNR进行。由华盛顿大学牵头的一项综合教育、培训和推广计划将涵盖从四年级学生到实习工程师的各个阶段。将为教师和教授开发模块，可以插入到他们的课程中。研究小组将在夏令营、访问当地小学、初中和高中、本科和研究生课程以及继续教育课程中使用模块。具体方案针对的是代表性不足的群体。为实现其目标，该项目将利用NEESit网络基础设施、最先进的仪器设备和高速数据采集系统、位于联合国后勤基地和UIUC的NEES设备点以及位于UMR的非NEES设备点，后者已承诺加入NEESgrid。

NEESR-SG: Seismic Simulation and Design of Bridge Columns under Combined Actions, and Implications on System ResponseABSTRACTDavid Sanders, University of Nevada, Reno, PIAbdeldjelil DJ Belarbi, University of Missouri, Rolla, Co-PIShirley Dyke, Washington University, Co-PIAmr Elnashai, University of Illinois, Urbana-Champaign, Co-PIJian Zhang, University of California, Los Angeles, Co-PIBridge columns are subjected to combinations of actions and deformations, caused by spatially-complex earthquake ground motions, features of structural configurations and the interaction between input and response characteristics. Combined actions/loadings can have significant effects on the force and deformation capacity of reinforced concrete columns, resulting in unexpected large deformations and extensive damage that in turn influences the performance of bridges as vital components of transportation systems. These effects should be considered in earthquake analysis and design of bridges so that significant earthquake damage and severe disruption of transportation systems can be reduced. The objectives of the project are to develop a fundamental knowledge of the impact of combined actions on column performance and system response and to establish analysis and design procedures that include the impact at both the component and system levels. The objectives will be realized by integrating analytical and experimental research where physical tests are driven by analyses and simulations that examine the system response of various bridge types under different loading conditions. The analytical models are calibrated by experimental data and then extended to system response. The experimental program includes quasi-static testing of twenty-four large columns (fourteen will be funded by NEES) providing fundamental behavior including the impact of torsional moments at University of Missouri, Rolla (UMR), pseudo-dynamic testing of three large and four small scale columns with variable axial load, within a bridge system simulation, at the University of Illinois at Urbana-Champaign (UIUC), real-time dynamic testing of eight large scale columns with bidirectional, torsional and variable axial load inputs at University of Nevada, Reno (UNR), four tests provided by the University of Mexico (UNAM), plus an integrated experiment with three columns linked through simulation, conducted at UIUC by UMR. Fragility analysis will be undertaken, leading to the derivation of probabilistically-based fragility relationships for bridges subjected to combined action. Simplified analysis and design tools will be developed as well as the necessary code language to change the existing practice. Design and analysis methods will be derived that will affect the earthquake design practice in the US and internationally. Coordination of an integrated test program has already begun between the US and Japanese researchers. Analysis components will be done at UCLA, UIUC, UMR and UNR. An integrated education, training and outreach program, lead by Washington University, will span from 4th graders to practicing engineers. Modules will be developed for teachers and professors that can be inserted in their courses. Modules will be used by the research team in summer camps, visits to local elementary, middle and high schools, undergraduate and graduate courses and in continuing education courses. Specific programs are targeted towards underrepresented groups. To achieve its objectives, the project will utilize the NEESit cyber-infrastructure, state-of-the-art instrumentation and high-speed data acquisition systems, the NEES equipment sites at UNR and UIUC and the non-NEES site at UMR, which has committed to joining NEESgrid.