板柱节点冲切破坏后受力性能试验研究

发布时间：2018-06-15 03:11

本文选题：板柱节点 + 整体性钢筋　；参考：《建筑结构学报》2015年07期

【摘要】：完成12个钢筋混凝土板柱节点试件冲切破坏试验,通过改变剪跨比、纵筋配筋率和整体性钢筋布置方式,以期得到能够提高冲切破坏后承载力、避免连续倒塌的构造措施。试验结果表明,纵筋配筋率对承载力影响并不明显,纵筋较早发生锚固失效,对冲切破坏后承载力的贡献非常有限。整体性钢筋能够有效提高残余承载力和冲切破坏后承载力,剪跨比越大效果越明显。在大挠度情况下,整体性钢筋成为冲切锥体和剩余板的唯一连接,依靠整体性钢筋轴力的竖向分量和大挠度形成的力矩来抵抗外部竖向荷载的作用,试件破坏由整体性钢筋断裂或锚固失效控制,通过布置足量的整体性钢筋、提高混凝土强度以及增大钢筋保护层厚度等措施,可进一步提高冲切破坏后承载力。采用规范公式对试件冲切承载力和冲切破坏后承载力进行预测并与试验结果对比表明,预测值相比试验值偏差较大。最后给出了冲切破坏后承载力的建议计算式和构造措施,为我国相关规范的编写提供参考。
[Abstract]:Twelve specimens of reinforced concrete slab-column joints were subjected to punching failure tests. By changing shear span ratio, reinforcement ratio of longitudinal reinforcement and overall arrangement of reinforcing bars, the authors hope to obtain structural measures that can improve the bearing capacity after punching failure and avoid continuous collapse. The experimental results show that the reinforcement ratio of longitudinal reinforcement has no obvious effect on the bearing capacity. The anchoring failure of longitudinal reinforcement occurs earlier, and the contribution to the bearing capacity after shear failure is very limited. The whole steel bar can effectively increase the residual bearing capacity and the bearing capacity after punching failure, and the greater the shear span ratio is, the more obvious the effect is. In the case of large deflection, the integral steel bar becomes the only connection between the punching cone and the residual plate. It relies on the vertical component of the axial force and the moment formed by the large deflection to resist the action of the external vertical load. The failure of the specimen is controlled by the fracture of the whole steel bar or the failure of the Anchorage. The strength of the concrete and the thickness of the protective layer of the steel bar can be further improved by arranging sufficient amount of the whole steel bar and increasing the thickness of the protective layer of the steel bar. The punching capacity of the specimen and the bearing capacity after punching failure are predicted by the standard formula. The comparison with the test results shows that the predicted value deviates greatly from the experimental value. Finally, the proposed calculation formula and structural measures of the bearing capacity after punching failure are given, which provides a reference for the compilation of relevant codes in China.
【作者单位】：湖南大学土木工程学院;
【基金】：国家自然科学基金项目(51178175,51338004)
【分类号】：TU375.3

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