NEESR-CR: Post-Tensioned Coupled Shear Wall Systems

这个奖项是NSF 09-524计划征集的结果，“乔治E。小布朗地震工程模拟网络（NEES）研究（NEESR）”的竞争，包括圣母大学（牵头机构），得克萨斯大学泰勒（子奖），和利哈伊大学（子奖）。该项目将利用利哈伊大学的NEES设备场地。该奖项旨在研究地震区新结构系统的可行性，即，一种抗震钢筋混凝土（RC）耦合剪力墙系统，其中广泛使用的无粘结后张（PT）RC楼板构造方法适于耦合（即，连接）梁以在墙墩之间产生耦合力。本研究的目的是开发一种联肢墙系统，提供显着的性能，施工和经济效益，并在严重的地震过程中，承受小的损害，目前使用的剪力墙与对角加强连梁。 智力优势：主要的智力价值的研究是一个新的和更实用的类型的抗震钢筋混凝土耦合建筑墙系统的调查与传统系统的显着性能和经济效益。当前结构中的典型连梁难以构造（它们需要以复杂几何形状布置的大量钢筋）并且在地震载荷下可能经历相当大的损坏。相比之下，新系统连梁中的主要钢筋由单个无粘结PT钢筋束组成，大大简化了施工。该系统代表了一项重大的创新和变革，但可以通过利用现有和广泛使用的技术来实现。连梁的变形主要以端部开口的形式发生，在大地震期间结构横向位移时造成的破坏很小。地震发生后，PT筋提供恢复力，关闭间隙，并将结构拉回到其未变形的垂直位置。在地震区使用这些结构的唯一主要障碍是缺乏实验验证的设计方法，施工程序和数值模拟模型。为了填补这一知识空白，将进行大型物理实验室实验，并结合多层耦合墙结构的计算机模拟。实验室标本将包括前三层，支流板，和两个原型系统的基础，代表结构的最关键的区域。结构的其他（不太关键的）区域将在计算机中模拟，从而形成一个混合物理计算研究平台。实验室结构的变形将使用多个三维数字图像相关传感器进行监测，由此产生的近全场数据将为其他项目区域提供信息。最终，这些信息将导致开发的验证设计程序和建模/预测工具的新system.Broader影响：钢筋混凝土耦合墙建筑结构在美国很常见。该研究将通过寻求实际采用新型联肢墙系统，从而提高建筑经济性和减轻未来地震损失，为社会提供直接服务。执业工程师将参加咨询小组，与相关专业组织的互动将有助于将结果快速传播给最终用户。实施多传感器数字图像相关的建筑结构评估是另一个创新方面的工作，可以帮助在其他类似的研究计划中采用这项技术。 该研究团队包括教师和学生从一个主要的本科院校（得克萨斯大学泰勒）与一个新的和不断增长的土木工程系，其研究和教育活动将受到该项目的影响。研究人员还将利用该项目通过K-12课堂演示和远程呈现会议来教育未来的工程师。传播、外联和技术转让活动将利用NEEShub资源。该项目的数据将通过NEES数据库存档并向公众提供。该奖项是国家减少地震灾害计划（NEHRP）的一部分。

This award is an outcome of the NSF 09-524 program solicitation, "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the University of Notre Dame (lead institution), the University of Texas at Tyler (subaward), and Lehigh University (subaward). This project will utilize the NEES equipment site at Lehigh University. This award investigates the feasibility of a new structural system for seismic regions, i.e., a seismic-resistant reinforced concrete (RC) coupled shear wall system where the widely-used, unbonded post-tensioned (PT) RC floor slab construction method is adapted for coupling (i.e., link) beams to develop coupling forces between the wall piers. The research objective is to develop a coupled wall system that provides significant performance, construction, and economic benefits, and that sustains little damage during a severe earthquake, over currently used shear walls coupled with diagonally reinforced coupling beams. Intellectual Merit: The primary intellectual merit of the research is the investigation of a new and more practical type of earthquake-resistant RC coupled building wall system with significant performance and economic benefits over conventional systems. Typical coupling beams in current construction are difficult to construct (they require large amounts of reinforcing steel arranged in complex geometries) and can experience considerable damage under seismic loading. In comparison, the primary reinforcement in the coupling beams of the new system consists of a single unbonded PT tendon, greatly simplifying construction. This system represents a significant innovation and transformation, but one that can be realistically achieved by utilizing an existing and widely-used technology. The deformations in the coupling beams occur primarily in the form of gap opening at the ends, resulting in little damage as the structure displaces laterally during a large earthquake. After the earthquake, the PT tendons provide a restoring force that closes the gaps and pulls the structure back toward its undeformed, plumb position. The single major barrier to the use of these structures in seismic regions is the lack of experimentally-validated design methods, construction procedures, and numerical simulation models. To fill this knowledge gap, large-scale physical laboratory experiments integrated with computer simulations of multi-story coupled wall structures will be conducted. The laboratory specimens will include the first three floors, tributary slabs, and foundations of two prototype systems, representing the most critical regions of the structures. The other (less critical) regions of the structures will be simulated in the computer resulting in a hybrid physical-computational research platform. Deformations of the laboratory structures will be monitored using multiple, three-dimensional, digital image correlation sensors, and the resulting near-full-field data will inform the other project areas. Ultimately, this information will lead to the development of validated design procedures and modeling/prediction tools for the new system.Broader Impacts: RC coupled wall building structures are common in the United States. The research will provide direct service to society by pursuing the practical adoption of a new type of coupled wall system, thereby improving construction economy and mitigating future earthquake losses. Practicing engineers will participate in an advisory panel, and interactions with relevant professional organizations will facilitate rapid dissemination of the results to end users. Implementation of multiple-sensor digital image correlation for building structural evaluation is another innovative aspect of the work that can aid in adoption of this technology in other similar research programs. The research team includes faculty and students from a predominantly undergraduate institution (University of Texas at Tyler) with a new and growing civil engineering department whose research and educational activities will be impacted by this project. The researchers will also use the project to educate future engineers through K-12 classroom presentations and telepresence sessions. The dissemination, outreach, and technology transfer activities will utilize NEEShub resources. 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).