中国古代多层大木作结构振动台试验研究

发布时间：2018-09-19 16:09

【摘要】：与唐宋时期相比，明清时期的木结构古建筑在建筑外形和结构性能方面有较大差异：斗h1层抗侧刚度变大，构架卷杀简化，结构的整体性增强。西安城墙永宁门箭楼是明清时期典型的多层厅堂式结构，于1926年毁于兵燹，为恢复西安城墙完整的形制，对其进行复建，按现代对古建筑复建的要求，需对其抗震性能进行分析。本文以永宁门箭楼为原型，按照清工部《工程做法则例》的规制，设计制作了缩尺比为1:6的局部缩尺模型，并对其进行了地震模拟振动台试验，对加载过程中的试验现象进行了观察；分析了模型结构的位移反应（包括相对柱脚的位移反应、层间位移反应、层间位移角）、加速度反应（包括绝对加速度反应、各层及整体结构的动力放大系数）、层间剪力（各层剪力分布及剪力—层间位移滞回曲线）、节点弯矩及能量的输入及耗散情况，得出了以下结论：（1）随着台面地震激励的增大，模型结构节点刚度逐渐下降且变得均匀，扭转现象及扭转振型逐渐消失，结构的自振频率逐渐衰减，阻尼比逐渐增大，说明模型结构逐渐发生损伤；（2）柱脚及斗h1层具有了隔振作用；二层为模型结构的薄弱层；（3）在台面地震激励为兰州波500Gal时，二层层间位移角达到1/9，但是试验模型仍未倒塌，说明木结构古建筑在地震作用下具有良好的变形性能；（4）在模型结构中，柱架层的减震作用最大，说明榫卯节点具有良好的减振性能，抗震性能良好；（5）由于柱脚滑移隔震、榫卯节点转动耗能减震以及斗h1层这一柔性连接结构的存在，木结构古建筑属于长周期结构，其对短周期的地震波具有较好的隔震、减振作用，但受长周期地震波的影响较大；（6）结构的剪力分布很不规律，剪力最大值不时出现在结构的顶部、底部或中间；剪力—层间位移滞回曲线非常饱满，说明柱架层的耗能能力较强，抗震性能较好；（7）在耗能分配中，滞回耗能占的比例较大，占总耗能的64.93%~73.88%；在滞回耗能中，柱架的耗能能力较强，占滞回耗能总量的91.8%~95.4%，，在结构滞回耗能中起到主要作用，斗h1层因摩擦滑移而耗散的地震能量较少。
[Abstract]:Compared with the Tang and Song dynasties, the ancient wooden structures in the Ming and Qing dynasties had great differences in terms of architectural shape and structural performance: the lateral stiffness of the Dou H1 story became larger, the frame was simplified, and the integrity of the structure was enhanced. The Yongning Gate Arrow House of Xi'an City Wall was a typical multi-story hall structure in the Ming and Qing dynasties. It was destroyed in 1926 by Bingxian. In order to restore the intact shape of Xi'an city wall, it was rebuilt according to the requirements of modern ancient buildings. Its seismic performance needs to be analyzed. In this paper, a local scale model with a scale ratio of 1:6 is designed and manufactured according to the regulations of the Code of Engineering practice of the Ministry of Qing Dynasty and the Yongning Gate Arrow Tower as a prototype, and the shaking table test of earthquake simulation is carried out on the model. The experimental phenomena during loading are observed, and the displacement response (including displacement response relative to column foot, interstory displacement angle), acceleration response (including absolute acceleration response) of the model structure are analyzed. Dynamic magnification factor of each story and the whole structure), interstory shear force (shear force distribution and shear-layer displacement hysteretic curve), input and dissipation of joint moment and energy, The following conclusions are obtained: (1) with the increase of seismic excitation on the Mesa, the stiffness of the node of the model structure decreases and becomes uniform, the torsional phenomenon and torsional mode gradually disappear, and the natural vibration frequency of the structure decreases gradually. The damping ratio increases gradually, which indicates that the model structure is damaged gradually; (2) the column foot and the bucket H1 layer have vibration isolation effect; the second layer is the weak layer of the model structure; (3) when the Mesa earthquake excitation is Lanzhou wave 500Gal, The displacement angle between the two layers reaches 1 / 9, but the experimental model has not collapsed, which indicates that the ancient building of wood structure has good deformation performance under earthquake. (4) in the model structure, the column layer has the greatest effect on reducing earthquake. The results show that the joint has good vibration absorption and good seismic performance. (5) because of the sliding isolation of the column foot, the rotational energy dissipation of the tenon joint and the existence of the flexible connection structure of the bucket H1 layer, The wood structure ancient building belongs to the long-period structure, it has the good isolation, the vibration absorption function to the short-period seismic wave, but is greatly affected by the long-period seismic wave; (6) the shear force distribution of the structure is very irregular, The maximum shear force appears at the top, bottom or middle of the structure from time to time. The hysteretic curve of shear-interstory displacement is very full, which indicates that the column floor has strong energy dissipation capacity and good seismic performance. (7) in the distribution of energy consumption, Hysteretic energy consumption accounts for a large proportion, accounting for 64.933% of the total energy consumption, and 73.88% of the total energy consumption. In the hysteretic energy consumption, the column frame has a strong energy dissipation capacity, accounting for 91.8% of the total hysteretic energy consumption, which plays a major role in the structural hysteretic energy consumption. Less seismic energy is dissipated due to friction slip in the bucket h 1 layer.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU366.2

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