高延性混凝土加固单层砖木结构农房振动台试验研究

SHAKING TABLE TEST OF SINGLE-STORY BRICK-WOOD STRUCTURES OF RURAL BUILDINGS STRENGTHENED WITH HDC

  • 摘要: 为提高我国农村砌体房屋的抗震性能水平,采用高延性混凝土(HDC)条带加固的方法,设计了两个缩尺比为1∶2的砖木结构模型,对加固模型与未加固模型进行振动台同台对比试验。对比分析了地震作用下两个模型结构的加速度响应、位移响应、扭转效应和破坏形态,并对其抗震性能进行评估。试验结果表明:单层砖木结构农房的整体抗震性能较差,结构的自振频率低、位移反应较大,扭转效应明显,在8度设防地震作用下接近倒塌;经HDC条带加固的模型结构自振频率增大,位移反应相比未加固模型更小,山墙外闪现象得到明显控制,结构扭转效应的破坏作用明显减轻,在9度罕遇地震作用下HDC面层只出现轻微受损,可达到“大震可修”的性能目标。采用HDC条带加固法可有效延缓结构在强震作用下的刚度退化,增加结构的耐损伤能力,并有效提高此类砌体结构的整体抗震能力。

     

    Abstract: In order to study the seismic performance of rural masonry buildings strengthened with high ductile concrete (HDC), the shaking table tests were performed on two brick-wood structures with a scale of 1/2. The first model was unreinforced, and the second model was reinforced by HDC. The two models were compared in terms of natural frequency, acceleration response, displacement response, torsional effect and failure mode. The seismic performance of the two models was evaluated. Test results showed that the unreinforced model had lower self-oscillation frequency, larger displacement response and more pronounced torsion effect. The unreinforced model was severely damaged under the design basis earthquakes. The strengthened model had larger self-oscillation frequency, slower stiffness degradation and smaller displacement response than the unreinforced model, the out-of-plane deformation of brick gables was controlled clearly, and the damage due to structural torsion was significantly reduced. Marginal damage was caused to the HDC surface layer under the rare earthquakes conditions. The strengthened model can achieve the performance target of 'repairable under rare earthquakes'. The application of the retrofit system is expected to improve the overall seismic capacity of the structure.

     

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