RAPID: Evaluation of Analytical Assessment Tools through Comparisons to Observed Seismic Performance in the January 2010 Haiti Earthquake

2010年1月12日，海地7.0级地震严重破坏了首都太子港的几座现代工程建筑。该研究项目将收集有关这些结构的观察性能的易腐数据，以便与地震评估程序中使用的基于分析的响应预测进行比较和校准。这项研究是学术界和工业界的合作，大学研究人员与地震工程咨询公司Rutherford and Chekene的专业人员一起工作。该项目依赖于与加拿大舍布鲁克大学的一位教员的密切合作，这位教员已经建立了联系，并掌握了海地实地情况的第一手资料。本研究的目的是：(1)对海地地震中一类结构的损坏进行分类和分类；(2)将结构体系、布局、设计和详图的损坏联系起来；(3)评估当前评估中使用的分析技术和程序的有效性。预期的研究成果是一份报告文件：(1)结构/场地描述；(2)设计资料；(3)灾后状态记录；(4)分析技术和模型说明；（五）分析结果和比较；(6)方法评价。研究将包括对设计、现场条件和少量重要工程结构（学校、研究所、政府大楼）观察到的损坏情况的记录，重点是钢筋混凝土结构。候选建筑已经确定，所有在首都太子港，根据损坏情况，现有的设计信息和可达性。候选结构的抗震性能将主要通过研究小组和合作者在海地的现场目视检查获得。检查将包括失效模式，损坏强度和模式，以及残余状态。现有的信息将用于构建分析模型，使用最先进的技术进行非线性动态分析。地震危险等级将通过索引产生观测到的损害所需的需求水平来估计。在此过程中，分析模型将进行增量动态分析，以便将观测到的损伤映射到USGS震动图中可用的参考振幅。然后，可以使用美国常用的公认地震评估技术（线性、非线性、静态和动态）对观测到的响应进行预测，并与观测到的实际性能进行比较。特别是，结构模型的有效性，以产生类似的行为模式，损伤的整体模式，和适当的评估决策将进行评估。通过对预测反应与实际结果的比较，得出这些方法有效性的结论。对各种参数和模型校准的响应灵敏度进行初步评估。在可能的情况下，将作出预测对不同变量的敏感性和对不确定性的估计。这项工作收集了实际地震事件中建筑物性能的易损信息，并有可能为地震评估的关键步骤提供信息，即模型校准。这项研究进一步扩展了钢筋混凝土结构在地震中的抗震性能知识。这项研究的潜在影响是通过改进的分析模型和评估技术以及改进的改造评估，提高公共安全和有关基础设施改造和升级的更明智的决策。该项目提供的信息可广泛用于地震工程研究。项目成果将通过行业合作伙伴参加专业小组和委员会的方式提供给专业人士。项目调查人员还将在2010年夏季或秋季海地地震RAPID奖的研讨会上展示研究结果。

The magnitude 7.0 January 12, 2010, Haitian earthquake severely damaged several modern engineered buildings in the capital city of Port-au-Prince. This research project will gather perishable data on the observed performance of these structures for the purposes of comparison with, and calibration of, analytically-based response predictions used in seismic assessment procedures. The research is a partnership between academia and industry with university researchers working alongside professionals from the earthquake engineering consultant firm, Rutherford and Chekene. The project relies on close collaboration with a faculty member at the Université de Sherbrooke, Canada, who has established contacts and first-hand knowledge of the conditions on the ground in Haiti. The objectives of the research are to: (1) catalog and classify damage for a class of structures in the Haiti earthquake; (2) correlate damage to structural system, layout, design and detailing; and, (3) evaluate the efficacy of analytical techniques and procedures used in current assessment. The expected research outcome is a report documenting: (1) structure/site description; (2) design information; (3) documentation of post-earthquake state; (4) description of analytical techniques and model; (5) analytical results and comparisons; and (6) evaluation of the methods. The research will involve the documentation of the design, site conditions, and observed damage on a small set of important engineered structures (schools, institutes, government buildings), focusing on reinforced concrete construction. Candidate structures have been identified, all within the capital city of Port-au-Prince, on the basis of damage state, available design information, and accessibility. Seismic performance of the candidate structures will be obtained primarily from on-site visual inspection in Haiti by the research team and collaborators. Included in the inspection will be failure modes, damage intensity and patterns, and residual state. The available information will be used to construct analytical models using state-of-the-art techniques for nonlinear dynamic analysis. Seismic hazard levels will be estimated by indexing to the level of demand required to bring about the observed damage. In this process, the analytical models will be subjected to incremental dynamic analysis in order to map the observed damage to reference amplitudes available from USGS shake maps. Then, predictions of the observed response can be conducted using accepted seismic assessment techniques common in the U.S. (linear, nonlinear, static, and dynamic) and compared to the observed actual performance. In particular, the effectiveness of the structural models to produce similar behavior modes, overall patterns of damage, and appropriate assessment decisions will be evaluated. Conclusions on the efficacy of these methods will be drawn through comparisons of the predicted response to actual outcomes. Preliminary evaluation of the sensitivity of the response to various parameters and model calibration will be performed. Where possible, the sensitivity of the predictions to different variables and estimations of uncertainty will be made. This work gathers perishable information on building performance in actual seismic events and has the potential of providing information on a key step in seismic assessment, namely calibration of models. This research additionally extends knowledge on seismic performance of reinforced concrete structures in earthquakes. The potential impact of this research is increased public safety and more informed decision making pertaining to infrastructure retrofit and upgrading through improved analytical models and assessment techniques, as well as improved retrofit evaluations. The information provided by this project can be used widely by earthquake engineering researchers. Project results will be made available to the profession through the industry partners' participation in professional groups and committees. Project investigators will also present results of the study at a workshop for Haitian earthquake RAPID awards in summer or fall of 2010.