异形截面多腔钢管混凝土巨型分叉柱抗震机理研究

Seismic performance and design theory of the substructure with special-shaped concrete-filled steel tube tree megacolumns will be investigated based on the major project of Z15 building in Beijing. The tree megacolumn substructure consists of the special-shaped multi-cell concrete-filled steel tube megacolumns at the bottom and the tree megacolumns at the upper part connected by the tree megajoints in the middle of the building. The low cyclic loading test will be systematically conducted on the bottom huge size special-shaped concrete-filled steel tube megacolumns, and the tree megacolumns substructure in order to investigate their seismic performance under different construction details, horizontal loading in different directions, and different axial forces. Based on combination of experimental study, theory analysis and numerical simulation, the load bearing capacity, stiffness and its degradation process, ductility, hysteretic behavior, energy dissipation capacity and damage evolution will be analyzed, and the seismic mechanism will be revealed. Combined with the tree megacolumns substructure in Z15 building, and considering the common demand of similar projects, the element constitutive relations and numerical analysis model will be established. The simplified computing load bearing capacity model and resilience model will be presented. The practical seismic design method and construction details will be provided. The seismic theory and technique of tree megacolumns will be developed so as to lay the foundation for engineering applications.

以北京Z15大厦为重大工程依托，针对超高层建筑异形截面多腔钢管混凝土巨型分叉柱框架抗震设计关键科学问题，即“底部超大异形截面多腔钢管混凝土巨型柱-巨型分叉节点-上部巨型分叉柱”构成的巨型分叉柱子结构抗震性能与设计方法问题：较系统地进行底部超大异形截面多腔钢管混凝土巨型柱、巨型分叉柱子结构的低周反复荷载试验，研究其在不同构造型式、不同水平力作用方向、不同轴力作用方向下的抗震性能；采用试验研究、理论分析、数值模拟相结合的方法，分析其承载力和刚度退化过程、延性、滞回特性、耗能及损伤演化过程，揭示抗震机理；结合Z15大厦异形截面多腔钢管混凝土巨型分叉柱子结构工程设计，兼顾类似工程共性需求，建立单元本构关系和数值分析模型，提出承载力计算模型和恢复力模型，给出实用抗震设计方法和构造措施；发展巨型分叉柱抗震理论与技术，为工程应用提供支撑。

依托北京“中国尊”（Z15）超高层建筑，针对异形截面多腔体钢管混凝土巨型分叉柱框架抗震设计关键科学技术问题，较系统地进行了不同参数的底部超大异形截面多腔钢管混凝土巨型柱、巨型分叉柱子结构的低周反复荷载试验，研究了不同构造型式、不同水平力作用方向、不同轴力作用方向对其抗震性能的影响；在试验基础上，进行了理论分析及数值模拟，分析了其承载力和刚度退化过程、延性、滞回特性、耗能及损伤演化过程，揭示了其抗震机理；结合北京“中国尊”大厦异形截面多腔钢管混凝土巨型分叉柱子结构工程设计，兼顾类似工程共性需求，建立抗震分析模型，给出了实用抗震设计方法和构造措施并已应用于工程。试验及分析表明，“底部超大异形截面多腔钢管混凝土巨型柱-巨型分叉节点-上部巨型分叉柱”构成的巨型分叉柱子结构具有良好的抗震性能；工程应用表明，这种异形截面多腔钢管混凝土巨型柱性价比较好，施工方便，具有良好的应用前景。