拼装抱箍加固穿斗式木结构传统民居振动台试验研究

SHAKING TABLE TEST FOR REINFORCEMENT OF TRADITIONAL DWELLINGS OF CHUAN-DOU TIMBER STRUCTUREBY ASSEMBLED HOOPS

  • 摘要: 为提高节点严重残损的穿斗式木结构的抗震性能,采用刚度可调的拼装抱箍对预设残损的试验模型进行加固,并对完好结构及加固结构的抗震性能进行模拟地震振动台试验。试验选取El Centro波、Taft波、汶川波及人工波作为地震输入,对比完好结构及加固结构各工况下的动力特性及地震响应规律。同时,利用抗震鉴定规范评估试验模型的抗震性能,并结合累积耗能指标定量化评估拼装抱箍的加固效果。结果表明:多遇地震(0.035 g)下,两个模型均处于弹性阶段,整体结构响应基本一致。罕遇地震(0.220 g)下,加固结构二层柱顶动力系数衰减大于完好结构。此外,加固结构的整体位移响应小于完好结构,层间位移角由1/81降低至1/109,结构整体扭转响应也有所下降。采用累积耗能指标评估罕遇地震作用下结构耗能,整体与加固层分别提升21.02%和4.30%。这一切表明:刚度可调的拼装抱箍可以有效提升传统木结构的抗震性能,累积耗能指标可以有效弥补现行抗震鉴定标准对加固效果定量化评估的不足。

     

    Abstract: To enhance the seismic performance of Chuan-dou timber structures with severely damaged nodes, the test model with predetermined damage was reinforced assembled clamp hoops with adjustable stiffness. Shaking table tests were conducted to simulate the seismic response of both the intact structure and the reinforced structure. Four types of seismic inputs, namely El Centro wave, Taft wave, Wenchuan wave, and artificial wave, were selected to investigate the dynamic characteristics and seismic response behavior under diverse working conditions. Simultaneously, the seismic performance of the test model assessed using the Seismic Assessment Code, while the reinforcing effect of the assembled clamp hoops quantitatively evaluated through the dissipation index of structure. The results show that both models are in elastic phase under the frequent earthquakes (0.035 g), and their overall structural responses remain basically identical. For the maximum considered earthquakes (0.220 g), the power coefficient of the reinforced structure at the top of the second floor column is more significantly attenuated compared to the intact structure. Moreover, the overall displacement response of the reinforced structure is smaller than that of the intact structure, the interstory displacement angle decreases from 1/81 to 1/109 and the torsional response of the structure decreases. Assessing the structural energy dissipation under the maximum considered earthquake, the cumulative energy dissipation index reveals an increase of 21.02% for the overall structure and 4.30% for the reinforced floors, respectively. The experimental results demonstrate that the assembled clamp hoops with adjustable stiffness can effectively improve the seismic performance of Chuan-dou timber structures. Furthermore, the cumulative energy consumption index can effectively make up for the inadequacy of the current seismic appraisal standards for quantitative assessment of reinforcement effects.

     

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