Shear Design Method for Reinforced Concrete Interior Beam-Column Connections

这是三年研究项目的最后一年，准备了一份研究报告。主要研究成果总结如下：1。通常认为梁柱连接中的剪力是通过桁架机制和支撑机制来抵抗的，但由于梁屈服后节点内的粘结抗力难以维持，因此桁架机制并不可靠。在梁柱连接处设置侧向配筋对抗剪承载力没有贡献，但对剪力开裂后的连接处有有效的约束作用；横向梁在正交地震荷载作用下，即使经过弯折屈服，也能有效提高节点的抗剪能力。板也被发现有效地增加连接的抗剪能力。根据上述研究结果，提出了防止节点内剪切破坏的设计准则，其层间位移角不超过0.02或梁的延性系数不超过4.0；即1。连接处的剪应力应保持在混凝土抗压强度的0.25倍以下；如果在连接处连接横向梁，则可将剪应力水平限制放宽至混凝土强度的0.33倍。

This is the final year of three-year research project, a research report was prepared. Major research findings are summarized below :1. Shear in a beam-column connection is normally considered to be resisted by truss mechanism and strut mechanism, but the truss mechanism is not reliable because the bond resistance is difficult to maintain within the connection after beam yielding,2. The lateral reinforcement placed in the beam-column connection does not contribute to the shear resistance, but is effective confining the connection after shear cracking,3. The transverse beams, even after flexural yielding under orthogonal earthquake loading, are effective in increasing shear resistance of the connection,4. Slab was also found effective in increasing shear resistance of the connection.From the above research findings, design criteria are proposed to prevent shear failure within the connection up to a story drift angle of 0.02 or to a beam ductility factor of 4.0 ; i. e.,1. The shear stress in the connection should be kept below 0.25 times the concrete compressive strength,2. If transverse beams are connected to the connection, the limit on shear stress level may be relieved to 0.33 times the concrete strength.