摇摆防屈曲支撑-框架新型结构体系抗震性能研究

Based on systematical study on buckling-restrained braced frame system, an innovative rocking buckling-restrained brace - frame system which absorbed many advantages of existing structures has been invented, aiming at decreasing the damage and reducing the repair cost of building structures after strong earthquakes. The rocking system is developed based on buckling-restrained braced frame by changing the fixed restrained condition of buckling-restrained braced frame columns into the vertically relaxed tensile restrained condition, which is carried out by setting energy dissipating dampers between the buckling-restrained braced frame column end and base. Consequently, the buckling-restrained braced frame columns are allowed to uplift in a strong earthquake and then the rocking of buckling-restrained braced frame is involved. The rocking system has the seismic and energy dissipating mechanism that the buckling-restrained braces are supposed to be yielding firstly and dissipate the most energy, then dampers, and finally the beams and columns. Since the rocking system has excellent energy dissipating capacity and the advantage of easy repair, it is suitable for low/mid/high-rise buildings in the areas of highly seismic region. In this proposal, the seismic performance and damage distribution mechanism of the rocking system are planned to be investigated by theoretical analysis and pseudo-dynamic testing. The final goal is to develop the seismic design method of the rocking system. It is hoped that the research would contribute to the development of innovative seismic structure systems in our country.

为减少强烈地震中主体结构的破损程度，降低结构修复成本，实现震后快速恢复结构功能，本项目基于前期对防屈曲支撑框架结构体系的系统研究，借鉴和汲取目前已有抗震结构体系的优点，提出一种摇摆防屈曲支撑-框架新型结构体系。该结构体系是在防屈曲支撑框架结构体系基础之上的发展，通过在防屈曲支撑框架柱端与基础之间设置耗能阻尼器，以此放松支撑框架柱端与基础之间的受拉约束，在强烈地震中允许支撑框架柱端抬起，产生结构摇摆。该结构体系具有防屈曲支撑、耗能阻尼器、框架梁等多道抗震防线，具有结构抵抗、防屈曲支撑和阻尼器消能、结构摇摆等多重抗震机制，耗能能力强且易于修复，整体抗震性能好，应用在多高层建筑中具有显著的优越性。本项目拟通过理论分析和结构模型的拟动力试验研究，揭示摇摆防屈曲支撑-框架结构体系的抗震性能和损伤分布机理，提出该结构体系的抗震设计方法。

本项目基于前期对防屈曲支撑框架结构体系的系统研究，借鉴和汲取目前已有抗震结构体系的优点，提出一种摇摆防屈曲支撑-框架新型结构体系。该结构体系是在防屈曲支撑框架结构体系基础之上的发展，通过在防屈曲支撑框架柱端与基础之间设置耗能阻尼器，以此放松支撑框架柱端与基础之间的受拉约束，在强烈地震中允许支撑框架柱端抬起，产生结构摇摆。该结构体系具有防屈曲支撑、耗能阻尼器、框架梁等多道抗震防线，具有结构抵抗、防屈曲支撑和阻尼器消能、结构摇摆等多重抗震机制，耗能能力强且易于修复，整体抗震性能好，应用在多高层建筑中具有显著的优越性。.课题组采用动力弹塑性时程分析方法对防屈曲支撑框架结构和摇摆防屈曲支撑框架结构进行对比分析研究，完成了新型防屈曲支撑耗能阻尼器和摇摆耗能柱脚的研发，进行了防屈曲支撑耗能阻尼器试验、摇摆防屈曲支撑框架低周往复试验和摇摆防屈曲支撑框架结构子结构拟动力试验，并在理论分析和试验结果的基础上提出了摇摆防屈曲支撑的设计方法，项目的重要结果和意义如下：.（1）新型摇摆防屈支撑-框架结构体系解决了当前防屈曲支撑应用于混凝土框架结构中基础受拉的设计难题，拓宽了防屈曲支撑在高层混凝土结构工程中的应用范围；.（2）摇摆机构的设计使得此类结构的层间位移角更加均匀合理，嵌固式摇摆柱脚可以显著减小结构底柱中的轴向拉力和压力，充分保护了结构中重要的竖向承重及抗侧力构件，采用本项目所提出的设计方法能够保证结构在地震作用下具有合理的屈服机制以及耗能机制；.（3）新型摇摆防屈曲支撑框架结构体系具备了防屈曲支撑耗能、柱脚阻尼器耗能、主体结构（框架梁、柱）耗能以及结构摇摆等多重耗能和抗震机制，充分发挥了消能减震结构抗震的优点。.（4）基于项目研发的各种新型防屈曲支撑耗能阻尼器为减震结构的设计提供了更多选择，项目的理论分析成果和试验数据为防屈曲支撑结构的进一步研究和此类结构的工程应用提供了很好的理论和数据支持。