残损古建筑木结构基于耗能技术的抗震增强研究

Ancient timber structures, as non-renewable precious cultural heritage, were always damaged in earthquakes and need to be repaired and strengthened urgently. Therefore, a composite seismic enhancement technology with energy dissipation was developed by using some energy dissipation units in structures coupled with the wood infilled walls. Through the pseudo-static tests conducted on the energy consumed mortise-tenon joints and timber frames filled with wood walls, their aseismic strengthening mechanisms were reveled, seismic performances grasped and the restoring force models and simplified analysis methods established. Finite element models and seismic response analysis methods of whole ancient wooden structures with energy dissipation units were established, and testified via the earthquake simulation shaking table tests of the whole structural mode, based on which the influences of parameters of energy dissipation units and stiffness of timber infilled walls on the reinforcement effects were investigated. By taking into consideration of the security of the ancient timber structures and the value of them as heritage, the performance level and performance objective of the structures were determined. The relationship between the performance objective—inter-storey drift and the performance level was established, based on which the energy dissipation design parameters of the mortise-tenon joints and the wood frames with infilled wood walls were determined according to the seismic performance degradation and aseismic enhancement target of damaged ancient timber structures. Then the aseismic performance enhancement design theory was established. The research works have important scientific significance and social benefits for improving the ability of earthquake prevention and disasters reduction of ancient timber structures and for their long inheritance.

古建筑木结构是不可再生的珍贵文化遗产，但各种残损导致其抗震能力不足而在地震中损毁，亟待修缮增强。通过设置少量耗能增强元件和发挥木隔墙的耗能增强作用，发展一种复合抗震增强技术。通过耗能榫卯节点和耗能木隔墙框架的拟静力试验，揭示其抗震增强机理，掌握其抗震性能，建立其恢复力模型和简化分析方法。建立带耗能元件整体结构的地震反应分析方法和有限元分析模型，并通过振动台试验验证，在此基础上确定耗能元件参数、木隔墙参数等对结构抗震增强效果的影响规律。考虑结构本体安全、所传承文物价值等的不同需求，确定古建筑木结构的性态水平与性态目标。建立性态水平与性态指标层间位移角的相关关系，在此基础上根据残损结构的抗震性能退化情况和抗震增强性态目标，建立耗能榫卯节点、耗能木隔墙框架各项设计参数的计算方法，从而建立基于性态的抗震增强设计理论。研究成果对提升残损古建筑木结构的防震减灾能力而久远传承具有重要科学意义和社会价值。

古建筑木结构是不可再生的珍贵文化遗产，但各种自然和人物灾害使得现存绝大部分古建筑木结构处于不同程度的残损状态、抗震能力不足而在地震中容易损毁，亟待采取科学合理对策提升其抗震能力。发展一种与古建筑木结构自身“以柔克刚”抗震机制一致的基于耗能的抗震增强技术，建立能考虑结构本体安全、所传承文物价值的不同需求的抗震增强设计理论，是现存残损古建筑木结构抗震增强的攻关方向之一。项目通过设置少量耗能增强元件和发挥木隔墙的耗能增强作用，研发了一种榫卯节点摩擦耗能增强技术和一种SMA-木隔墙复合抗震增强技术。通过耗能增强榫卯节点和木隔墙耗能增强框架的拟静力试验，揭示了其抗震增强机理，掌握了其抗震性能，建立了其恢复力模型和简化分析方法。建立了采用耗能增强技术的残损古建筑木结构的地震反应分析方法和有限元分析模型。以西安钟楼为研究对象，对其1/6缩尺结构模型进行了地震模拟振动台试验研究，并从能量耗散角度、变形等各方面对比分析了木隔墙增强对结构抗震性能的影响，同时对地震反应分析方法和有限元分析模型进行了验证。在此基础上通过有限元分析模型分析了耗能榫卯节点、木隔墙框架增强对结构增强效果的影响规律。考虑结构本体安全、所传承文物价值等的不同需求，提出了残损古建筑木结构的抗震增强性态水平与性态目标。在此基础上根据残损古建筑木结构的抗震性能退化情况和抗震增强目标，确定了耗能榫卯节点、耗能木隔墙框架的各项设计参数，从而建立了古建筑木结构的抗震性态增强设计理论。研究成果对提升现存残损古建筑木结构的防震减灾能力及其久远传承具有重要科学意义和社会价值。