高层木框筒混合结构体系抗震性能及设计方法研究

Driven by the concept of Green Ecology, the high-rise building of timber structures has become a worldwide construction hot spot. The timber frame-core tube composite structure is the prior structural choice of constructing high-rise buildings of timber structures, however, systematic research at home and abroad is scarce. Revealing the mechanism of collaborative work between the external timber frame and the internal core tube, inventing the energy-consuming connectors, studying the seismic performance of the composite structure system and establishing the reliable design methods are of great significance to the development of high-rise timber buildings. At the first place, this project intends to systematically analyze the feasible structural schemes and the engineering cases of the timber frame-core tube composite structure and reveal the performance variation rules of the timber frame system and the core tube system. By establishing a timber frame-core tube numerical model and carrying out structure system optimization study, analyzing the multi-parameter coupling including stiffness, the bearing capacity, size and relative position could help to reveal the mechanism of collaborative work between the external timber frame and the internal core tube. Based on the mechanism of shock absorption, new types of energy-consuming connectors would be invented. The project will reveal the stress mechanism of these connectors and study the influences of the performance of these connectors on the collaborative work between the external timber frame and the internal core tube which would be combined with the numerical model analysis of the timber frame-connectors-core tube and the relative theoretical and experimental studies. Then, the recovery force model of those connectors will be proposed. The next step is that combining the nonlinear dynamic analysis of the refined numerical model of the composite structural system, the theoretical study and the shaking table test will be carried out to obtain the seismic performance of it. The method of shear distribution and calculation of stiffness will be proposed to establish a seismic design method in line with China's current standard system.

在绿色生态理念驱动下，高层木结构建筑已经成为世界性工程建设热点，木框筒混合结构体系是高层木结构工程应用优选的结构解决方案，但国内外尚缺系统研究。揭示框筒协同机理，研发耗能连接形式，掌握体系抗震性能，建立可靠设计方法，对木结构向高层发展具有重要意义。本项目系统分析木框筒混合结构体系的可行结构方案及工程案例，揭示木框架与核心筒体系的性能变化规律，建立木框架-核心筒数值模型并开展体系优化，分析木框架与核心筒刚度、承载力、尺寸及相对位置等多参数耦合作用，揭示其协同机理；依据减震机理研发新型耗能连接形式，结合木框架-连接-核心筒数值模型分析，通过理论和试验研究揭示其受力机理及对框筒协同工作的影响规律，提出连接恢复力模型；结合混合结构体系精细化数值模型非线性动力分析，开展理论研究和振动台试验研究，得到其抗震性能，提出混合结构体系剪力分配方法和刚度计算方法等，建立符合我国现行标准体系的抗震设计方法。

随着国家“碳中和”目标的提出与实践，木结构成为建筑行业中实现全建设周期低碳环保的重要组成部分。国际上越来越多的高层木结构建筑的建设与创新都体现出了其战略性地位。其中，高层木结构的抗震性能与设计方法研究对木结构抗震理论的进一步发展具有重要意义，同时为我国高层木结构相关规范的编制提供依据。.本项目针对现代木结构与混凝土结构的力学特点，基于高层木框架-混凝土核心筒混合结构的节点、楼盖及整体结构开展分析、试验和理论研究，明确了地震作用下高层木框架-混凝土核心筒混合结构抗震性能，提出了高层木框架-混凝土核心筒混合结构的抗震理论和设计方法。.本项目主要研究内容有：.1）对高层木结构建筑的主要结构体系开展对比分析研究，分析木框架半刚性节点对整体结构抗震性能的影响规律，明确木框架-混凝土核心筒混合结构的受力特点与破坏机理，探明混合结构中框架与核心筒地震作用下的协同工作机理；.2）开展了CLT板相关的力学性能研究，包括CLT板抗剪性能与抗弯性能、CLT板连接的力学性能、CLT板梳妆连接力学性能、木肋-ALC组合楼板的抗弯性能及CLT-混凝土组合楼盖的抗弯性能研究等，提出了CLT板抗弯性能的计算方法与设计方法，掌握了高层木结构水平抗侧力体系的受力机理；.3）研究了木框架-混凝土核心筒混合结构体系地震作用下的弹塑性抗震性能，提出了木框架-混凝土核心筒混合结构抗侧刚度的计算方法与抗震设计方法，为高层木结构发展奠定基础。.本项目建立的高层木框架-混凝土核心筒混合结构的抗震设计方法可明显提高高层木结构的抗震性能，结构受力更加合理可靠，结构造价降低。与混凝土结构相比，高层木框架-混凝土核心筒混合结构在建设工程中可以大量降低碳排放，对降低实际工程建设成本、推广高层木结构建筑及保护环境具有重大指导意义。