体外预应力自复位框架结构抗震性能研究

External Prestressing Self-centering Frame (EPSCF) structure is a new type seismic-reducing structural system with energy-dissipating, which is derived and developed from the existing rocking structures. Refer to the index of Performance-Based Seismic Design and improved from some existing rocking structures, the objective of this research project is developing EPSCF to be a resilient structure. Based on the modern structural control theory and technology, the technical features of EPSCF are (1) the conventional solid column-beam joints are substituted by hinge joints, then the lateral-resistance stiffness of the structure is weaken and the earthquake action on the structure is reduced; (2) ingeniously installed prestressing tendons provide definite value of lateral-resistance stiffness and self-centering capability of the frame; (3) inter-storey energy-dissipating devices absorb earthquake energy and control the displacement response of the structure. The main research content of this project are the seismic-reducing mechanism of EPSCF, optimization of the seismic control parameters, setting-up of multiple seismic lines of defence, construction quality control and detail of non-structure components. Relative research will deal with the design methods of EPSCF structure and joints, design methods of wind-resisting and small-earthquake resisting devices, model selection of dampers, property parameters design, et al. The objectives of this project are developing an energy-dissipation aseismic structure with remarkable potential of engineering practice, realizing the seismic mechanism of EPSCF system and mastering the numerical simulation and design methods of EPSCF.

体外预应力自复位框架结构是一种新型耗能减震结构体系，是对已有摇摆结构研究成果的继承和发展。本项研究课题目标为可恢复功能结构，参考基于性能设计的抗震性能指标，对已有摇摆结构加以改进。依据结构控制抗震理论和技术，体外预应力自复位框架结构的技术特征为：将传统固结梁柱节点构造为铰节点，降低了结构抗侧刚度，减小结构地震作用；通过巧妙设置的预应力筋提供结构定值抗侧刚度和自复位能力；设置层间耗能装置来耗散地震能量并控制结构位移响应。研究内容包括体外预应力自复位框架结构减震力学机理研究、抗侧刚度及层间阻尼等结构控制参数的优化、设置多道抗震防线、结构施工质量控制及非结构构件构造研究等，另外还涉及结构整体设计、节点设计、抗风和抗小震装置设计、阻尼器的选型及参数设计、数值模拟方法等。课题研究目标是探索一种有工程应用前景的耗能减震结构体系，通过研究掌握其抗震力学机理，形成数值分析和设计方法。

体外预应力自复位框架（External Prestressed Self-centering Frame，EPSCF）结构是一种新型消能减震结构体系。EPSCF结构的三大主要技术特征为：（1）在柱脚和梁柱节点处采用纯铰接的连接方式，使框架结构具有足够的转动能力和变形能力；（2）采用体外预应力钢绞线提供地震作用下结构自复位的恢复力；（3）采用可替换的层间阻尼器，一方面耗散了输入到结构中的地震动能量，另一方面有效地控制了结构位移。主要研究内容包括单榀体外预应力自复位框架拟静力试验研究和数值模拟、体外预应力自复位框架减震的力学机理研究、体外预应力自复位框架的模拟地震振动台试验研究和数值分析，另外还涉及结构整体设计、节点设计、阻尼器的选型、参数设计、抗风和小震装置设计等。课题研究中分别完成了二维EPSCF和三维结构模型的模拟地震振动台试验，研究证明EPSCF结构体系具有优异的抗震性能，主体结构在地震作用下具有“免损伤”特性，符合当前发展“弹性恢复”结构的潮流，也具有很好的工程应用前景。此外，本课题还完成了新型梁端弹簧耗能节点自复位框架的拟静力试验研究。课题研究为探索和发展一种新型经济、安全的抗震减震结构做出了基础性研究。