钢板混凝土剪力墙拉弯剪性能试验研究

EXPERIMENTAL RESEARCH ON TENSION-BENDING-SHEAR BEHAVIOR OF STEEL PLATE-REINFORCED CONCRETE SHEAR WALLS

  • 摘要: 超高层建筑“细柔”特征容易引起底部剪力墙在强震下处于拉-弯-剪复合受力状态,中国《超限高层建筑工程抗震设防专项审查技术要点》(建质 201567 号)建议墙肢采用配置型钢/钢板的方式来改善该种抗震性能,但缺乏相关试验研究。为此,进行了6片钢板混凝土剪力墙的低周往复荷载试验,研究了轴拉比、含钢率及剪跨比对墙肢拉弯剪性能的影响。研究表明:拉弯剪作用引起钢板混凝土剪力墙密集的裂缝分布和显著的钢材强化,并导致其剪切-拉弯耦合破坏。轴拉比增大,墙肢承载力、初始抗侧刚度和延性分别降低22%、41%和39%;剪跨比减小,墙肢承载力和抗侧刚度至少提升23%;同时增大含钢率和降低剪跨比,墙肢延性提高10%。相比其他国家规范,中国规范对拉弯剪作用下钢板混凝土剪力墙的抗剪承载力预测效果更好,但其未能考虑高含钢率对裂面销栓力的影响,故建议采用暗柱的初始含钢率进行修正。

     

    Abstract: The bottom shear walls of flexible skyscrapers might be under tension-bending-shear (TBS) combined conditions during strong earthquakes. The Chinese code recommends configuring section steel to improve such seismic performance, but relevant experimental researches are limited. The low-reversed loading tests were performed on six steel plate-reinforced concrete shear walls (SPCW) to investigate the influences of tension ratio, steel ratio, and shear-to-span ratio on the TBS resistant performance. The results indicated that the TBS action led to a dense fracture distribution, prominent steel hardening, and a shear-tension bending coupled failure in SPCW. As the tension ratio increased, the bearing capacity, initial lateral stiffness, and ductility of SPCW decreased by 22%, 41%, and 39%, respectively. Reducing the shear-to-span ratio increased the bearing capacity and lateral stiffness of SPCW by at least 23%, while increasing the steel ratio and reducing the shear-to-span ratio improved the ductility by 10%. The Chinese code had a better prediction on the shear bearing capacity of SPCW under TBS actions than the codes of other countries. However, there was a lack of attention to the high steel ratio’s influence on the dowel force at fracture surfaces, so correction with the initial steel ratio of the concealed column was suggested.

     

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