钢-竹组合框架结构抗震性能与设计方法研究

Bamboo-steel composite columns and beams are built with bamboo plywood and cold-formed thin-walled steel sheet bonded by adhesives, which have high load bearing capacity, high stiffness, and consume relatively less materials. The seismic behavior of the bamboo-steel composite frame structure is crucial to ensure its global structural reliability. The project will systematically study the structural and mechanical characteristics of the bamboo-steel composite beam-column connections, analyze their failure modes and failure mechanisms under low cyclic loading and earthquake loading, explore evaluation methods for their structural seismic responses, and investigate how to improve anti-seismic performance of the composite frame structure. Through experiments and numerical analyses, the design of bamboo-steel composite beam-column connection is to be optimized, and the numerical restoring force model as well as the design method for the composite connection will be established. Meanwhile, coefficients and rules influencing their anti-seismic performance will be investigated. Nonlinear analytical method for its seismic response is to be proposed in order to reveal the different structural responses under different earthquake dynamic actions. Further, the methods to improve the composite frame structure’s anti-seismic performance will be proposed taking advantage of the energy dissipating connection and low yield point steel bracing. Based on the above results，simplified theory will be established for seismic response and structural deformation of the bamboo-steel composite frame structure, as well as the design methods for the composite structural components and anti-seismic connections. Finally, seismic design methods for bamboo-steel composite frame structure will be established within the seismic design system in China.

竹材人造板与冷弯薄壁型钢通过胶粘剂复合而成的钢-竹组合梁和组合柱，以较少的材料用量可获得较高的承载能力和刚度，由此构成的钢-竹组合框架结构体系，其抗震性能是保证整体结构可靠性的关键。本项目系统研究钢-竹组合梁柱节点构造及其受力特征，分析钢-竹组合框架结构在低周反复荷载与地震作用下的破坏机理和反应规律，探讨整体结构抗震性能提升措施以及结构地震反应评价方法。通过试验研究与计算分析，优化钢-竹组合梁柱节点构造，建立节点恢复力模型及设计方法，探明钢-竹组合框架结构抗震性能的影响因素及变化规律，并提出结构非线性地震反应分析方法，揭示不同地震动作用下的结构反应规律，在此基础上提炼基于耗能连接件节点和软钢支撑的抗震性能提升方法。综合以上研究结果建立钢-竹组合框架结构地震响应及结构变形的简化计算理论，并形成合理的结构构件与节点抗震验算方法，最终构建符合我国抗震设计体系的钢-竹组合框架结构抗震设计方法。

钢-竹组合结构工字形框架柱和框架梁由高强螺栓和连接件（或软钢支撑）组配形成钢-竹组合框架，具有施工便捷、传力可靠、抗震性能良好等特点。本项目设计了2种半刚性节点与4种耗能节点，通过拟静力试验观测各型节点在低周反复荷载作用下的滞回性能、耗能水平、破坏特征及强度、刚度退化规律，分析了节点构造参数与构造方式对节点抗震性能的影响，确定了节点在地震作用下的耗能机理。通过节点的参数化有限元分析，阐释了影响节点刚度、承载力、耗能水平及滞回特性的主要因素并明确其影响规律。设计制作了7榀两层单跨框架试件，包括普通框架1榀、耗能节点框架3榀与软钢支撑框架3榀，通过拟静力试验研究框架试件的抗震性能，对比分析了耗能节点对框架抗震性能提升效果，揭示软钢支撑对框架整体性能影响规律。采用时程分析法对框架进行了弹塑性地震响应分析，探究了框架试件在水平地震作用下的破坏机理与不同强度地震作用下的地震反应特征。对框架实施参数化的数值分析，研究了框架层间位移、内力分布规律与耗能水平，明确框架抗震性能主要影响因素及其规律。基于拟静力试验与数值分析结果，提出了钢-竹组合结构节点恢复力模型并分别建立节点、框架设计方法，包括内力计算方法、变形计算理论与抗震构造措施。研究结果表明，经合理设计的钢-竹组合框架结构具有良好的抗震性能与较高的耗能水平，可以在多高层钢-竹组合结构建筑中推广应用。本项目针对钢-竹组合结构的抗震性能进行了系统深入的研究，可促进钢-竹组合结构体系的实用化进程，有利于推动建筑业的绿色可持续发展。