Seismic Design and Parametric Response Evaluation of Unbonded Post-Tensioned Hybrid Coupled Walls

本课题研究的是混合墙体体系。混合墙系统还需要在以下几个方面进行进一步的研究：(1)开发新的和创新的混合墙连接和系统；(2)混合墙体系抗震性能参数评价。这个项目解决了这些需求。本研究的主要目的是分析研究一种新型混合耦合墙的抗震性能和设计，这种墙采用无粘结后张力来耦合墙体。与目前的工业实践和目前的研究相比，在混合耦合墙系统中使用无粘结后张拉是一项重大创新。该系统由钢筋混凝土墙和钢连接梁组成。预计采用无粘结后张法，可以简化连接梁和墙的细部设计。此外，预计通过使用无粘结后张拉，耦合梁可以设计成在“设计”水平地面运动期间基本上保持“无损伤”，大部分损伤发生在梁与墙连接的某些选定部件上，这些部件可以在地面运动后更换。研究任务包括：(1)建立和分析无粘结后张力杂化耦合壁的滞回行为模型；(2)对这些墙体进行参数化地震反应评估；(3)制定这些墙体的初步抗震设计建议和实际应用指南。将建立原型结构中耦合壁面的解析模型，并对这些壁面进行一系列参数化非线性静力和非线性动力时程分析。分析模型将使用利哈伊大学在无粘结后张拉钢框架组件上获得的实验结果进行验证，这些组件的连接类似于拟议系统中使用的耦合梁与墙的连接。基于非线性动力时程分析的结果，本研究将评估无粘结后张混合耦合墙的抗震性能，并制定实用的分析和设计程序以及实际应用指南。本项目由NSF 97-154项目第四年完成资助。这项研究的成功完成将为未来的实验研究提供一个分析基础，并可以制定规范化的设计规范。

The research conducted in this project is related to hybrid wall systems. Additional research is need on hybrid wall systems in the following areas: (1) development of new and innovative hybrid wall connections and systems; (2) parametric evaluation of the seismic behavior of hybrid wall systems. This project addresses these needs.The broad objective of this research is to analytically investigate the seismic behavior and design of a new type of hybrid coupled wall which uses unbonded post-tensioning to couple the walls. Compared with current industry practice and current research, the use of unbonded post tensioning, in a hybrid coupled wall system is significant innovation. The proposed system consists of reinforced concrete walls and steel coupling beams. It is expected t hat by using unbonded post-tensioning, the detailing of the coupling beams and the walls can be simplified. Furthermore, it is anticipated that by using unbonded post tensioning the coupling beams can be designed to remain essentially "damage-free" during a "design" level ground motion, with most of the damage occurring in certain selected components of the beam-to-wall connections which can be replaced after the ground motion.The research task include (1) developing and analytical models for the hysteric behavior of unbonded post-tension hybrid coupled walls; (2) performing a parametric seismic response evaluation of these walls; (3) developing preliminary seismic design recommendations and practical application guidelines for these walls. Analytical model of the coupled walls in the prototype structures will be developed and a series of parametric nonlinear static and nonlinear dynamic time history analyses of these walls will be conducted. The analytical models will be verified using experimental results obtained at Lehigh University on unbonded post tensioned steel frame subassemblages with connections similar to the coupling beam-to-wall connections used in the proposed system. Based on the results of the nonlinear dynamic time-history analyses, the research will assess the seismic behavior of unbonded post-tensioned hybrid coupled walls and develop practical analysis and design procedures and practical application guidelines. This project is supported under the 4th year completion of initiative NSF 97-154. Successful completion of the research will provide an analytical foundation on which future experimental research can be built and codified design specifications can be formulated.