带可更换构件的RCS混合框架结构地震损伤机制与功能可恢复评价标准研究

Aiming at the development trend of seismic design of engineering structures, a novel RCS hybrid frame structure system with energy-dissipation frame and replaceable beam was put forward based on the preliminary study on RCS composite frame structure. The frame can be used in building structure with large span or bearing heavy load. The earthquake action can be distributed properly between the hybrid frame members, in which the energy-dissipation frame consisted of replaceable beams is the main component to dissipate the earthquake energy . It is also the key members to realize earthquake resilience of the whole structure. Based on the seismic performance optimized analysis of the RCS hybrid frame structure, novel replaceable beam is developed to satisfy the cooperative working requirement. Through model test and numerical simulation, damage evolution law, damage mechanism and deformation of the replaceable beam are studied detailly. And the relation between damage degree and deformation of the beam are illuminate. Then the controls parameter and evaluation criterion used for replacement are put forward for the beam. For the whole hybrid frame structure, damage evolution law, yield mechanism and failure mode of each member are studied detailly. And the relation between damage or deformation of the beam or column and the whole frame are explicate. Then the controls parameter and evaluation criterion used to realize earthquake resilience of the whole structure are put forward. Based on those controls index, the seismic performance levels and performance targets of the hybrid frame structure are defined and described quantificationally. Then the earthquake resilience-base seismic design theory and method of the hybrid frame structure are put forward. The project can promote the development of the earthquake resilient structure and its seismic design theory, and is of great importance for promoting the application of this novel RCS hybrid frame structure.

契合工程结构抗震设计的新理念，在前期对RCS组合框架结构研究的基础上，提出一种带耗能框架和可更换钢梁的RCS混合框架结构体系。不但可用于大跨度、重荷载的建筑结构，还能实现地震作用在结构间的合理分配；主要由带可更换梁的耗能框架耗散地震能量，从而实现整体结构的功能可恢复。基于结构体系的优化分析，研发新型可更换钢梁，研究其地震损伤演化规律、破坏模式以及损伤程度与宏观变形的关系，提出其可更换性控制参数和评价标准。针对整体结构，研究结构各层次构件的地震损伤演化过程、屈服机制、破坏模式等，分析各层次构件损伤或变形与结构整体变形的关系，提出整体结构的功能可恢复性控制指标和评价标准。根据可恢复性控制指标，对结构的性能水平进行定量描述，提出适用于不同功能要求的结构抗震性能目标，以及基于功能可恢复的性能化抗震设计方法。研究成果可丰富功能可恢复结构体系及其抗震设计理论，对RCS混合框架结构的推广具有重要意义。

针对地震功能可恢复结构，提出一种带可更换构件的RCS混合框架结构体系，选取耗能框架与主框架弹性刚度比和弹性剪力比为控制参数，通过有限元模拟，从破坏过程、承载力和刚度等方面对结构的受力特性进行分析，结果表明：结构能实现预期受力状态，并且可得各控制参数的取值范围：弹性刚度比为1.3~4.3，弹性剪力比为1.5~4.0。.根据RCS混合框架结构体系有限元模拟结果，设计了四种形式的可更换梁，分别为整段式、三段式-中间段耗能、三段式-分阶段耗能及扩孔螺栓连接。通过拟静力试验，研究其损伤演化规律、破坏模式、损伤程度与宏观变形的关以及可更换性评价标准，结果表明，四种形式的可更换梁抗震性能和耗能能力较好，并且具有较好的可恢复功能。.对9个整段式耗能梁试件进行拟静力试验，对其抗震性能和可更换性能进行分析，结果表明，试件发生了剪切破坏和弯剪破坏两类，均具有稳定的承载力、变形能力、耗能能力，并且可更换能力较好。并对不同参数的整段式耗能梁进行有限元模拟，研究了不同参数对耗能梁抗震性能的影响，给出了相关设计建议。对10个三段式可更换梁进行拟静力试验，结果表明：试件发生剪切破坏，并且均能实现震后可更换，其可更换层间位移角范围为1/200~1/250。对不同参数的三段式可更换梁进行有限元模拟，结果表明，模型发生剪切破坏时抗震性能较好，长度系数宜取0.8~1.3，腹板高厚比宜取35.7~53.5。对6个扩孔螺栓连接的可更换梁进行拟静力试验，结果表明，试件均发生了剪切破坏，扩孔螺栓连接可显著提高试件的耗能能力。对长度系数不同的模型进行有限元分析，结果表明，长度系数对可更换梁破坏过程和破坏模式影响显著，宜取0.89 ~1.19 。.针对带可更换构件的 RCS 混合框架整体结构，研究结构各层次构件的地震损伤演化过程、屈服机制、破坏模式等，结果表明，塑性铰出现顺序为耗能框架中的耗能梁、RCS主框架中的钢梁、RCS主框架中的混凝土柱、耗能框架中的钢柱；以层间位移角为指标，结合结构构件的塑性铰分布与状态，提出了“三阶段四水平” 控制指标限值和评价条件；基于各层次构件变形与结构整体变形的关系，提出了整体结构基于性能的抗震设计方法。.研究成果可用于多层民用建筑、多层工业厂房，特别是大跨重载结构或有较高抗震性能要求的重要建筑。