强墙弱梁型钢筋混凝土梁-墙平面外连接节点试验

为研究剪力墙设置暗柱的钢筋混凝土梁-墙平面外连接节点的抗震性能,完成了6个按强墙(暗柱)弱梁设计的梁-墙平面外连接节点试件在梁端施加往复竖向荷载的试验,试件的主要变化参数为暗柱宽度、暗柱纵向配筋和梁纵筋在暗柱内的锚固。结果表明,6个试件在达到最大承载力前,梁的纵筋已屈服;梁纵筋在墙内锚固不足的试件,最终为剪力墙墙面混凝土局部拉脱破坏;暗柱宽度为梁宽3倍、梁纵筋在墙内锚固得到加强的试件,为梁弯曲破坏,具有大的变形能力;暗柱宽度为梁宽4倍的试件,梁、墙都发生破坏。在试验研究的基础上和参照现行国家标准,提出了剪力墙暗柱的设计建议:暗柱宽度不宜大于3倍梁宽;暗柱平面外弯矩设计值应根据梁端实配抗震受弯承载力确定;暗柱最小总配筋率不小于1.0%,箍筋最小直径为10mm、最大间距为150mm等。

Experimental study on strong wall-weak beam reinforced concrete non-planar beam-wall connection

To study earthquake resistant behavior of reinforced concrete(RC) non-planar beam-shear wall connection with built-in column in the shear wall,tests of 6 specimens were carried out under cyclic vertical loads applied at the cantilever beam end.All specimens were designed with strong wall(built-in column)-weak beam.The main parameters of the specimens included width of built-in column,reinforcement of built-in column and anchorage of beam longitudinal steel bars in the built-in column.Test results indicated that beam longitudinal bar yielding preceded the development of maximum load-carrying capacity.Tensile failure of wall concrete was occurred for the specimens that the anchorage of beam steel bars in the wall was not strengthened.The specimens with the width of built-in column being three times of the beam width and the anchorage of beam steel bars being strengthened had beam flexural failure corresponding to large deformation capacity.The specimens with the width of built-in column being four times of the beam width had the failure of both beam and wall.On the basis of the test results and the current standards the design recommendations of built-in column of non-planar beam-wall connection are presented,such as: the width of built-in column should not be larger than three times of the beam width,the out-of plane design moment of the built-in column should be determined according to the actual earthquake resistant moment capacity of the connecting beam,the minimum steel ratio of the built-in column should not be less than 1.0%,the minimum diameter of the stirrup is 10mm and the maximum space is 150mm,and so on.