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

本项目所进行的研究与复合墙体体系有关。混合墙体系还需要在以下方面进行进一步的研究：(1)开发新型和创新的混合墙连接和体系；(2)混合墙体系抗震性能的参数评估。本研究的主要目的是对一种新型无粘结后张法组合墙体的抗震性能和设计进行分析研究。与目前的行业实践和研究现状相比，在混合双肢墙体体系中采用无粘结后张法是一项重大的创新。该体系由钢筋混凝土墙体和钢连梁组成。预计采用无粘结后张法可以简化连梁和墙体的构造。此外，通过使用无粘结后张法，可以将连梁设计为在“设计”水平地震动期间基本上保持“无损伤”，大部分损伤发生在梁-墙连接的某些选定构件中，这些构件可以在地面运动后更换。研究任务包括(1)开发和分析无粘结后张法混合连体墙的滞回行为的模型；(2)对这些墙进行地震反应的参数评估；(3)为这些墙制定初步的抗震设计建议和实际应用指南。建立了原型结构中双肢剪力墙的分析模型，并对其进行了一系列的参数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获得的无粘结后张拉钢框架组件的试验结果进行验证，这些组件的连接类似于建议体系中使用的梁墙连接。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法混合双肢墙体的抗震性能，并制定实用的分析、设计程序和实际应用指南。该项目在NSF 97-154计划第四年完成的情况下得到支持。这项研究的成功完成将提供一个分析基础，以便在此基础上开展未来的实验研究，并制定出编撰的设计规范。

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.