ABSTRACT

Strength hierarchy assessment method is a capacity analysis procedure that can be used to identify the sequence of failures likely to occur within reinforced concrete (RC) frame buildings under lateral actions such as earthquakes or wind loads. Previous publication on this method mainly focused on the application of this method to (a) the vulnerable RC beam-column joints without any joint shear reinforcement where principal tensile stresses were considered critical, (b) modern RC beam-column joints with joint shear reinforcement where extreme principal compression stresses were considered critical. In this paper, joint shear capacity representation for modern RC beam-column joints (with transverse reinforcements in the joint) is generalized to include both critical components: principal tensile and principal compression stresses. Using strength hierarchy assessment, the investigation showed that it is possible to express the joint shear capacity as an N-M interaction envelope analogous to the N-M interaction of columns. The resulting joint shear capacity N-M interaction concept is validated using a database of 22 external and 22 internal RC beam-column joint tests with joint shear reinforcement at their joint core which resulted in joint shear failure in their tests. Considering the importance of axial load levels on the expected performance of RC beam-column joints, the proposed concept can be used for the general assessment of the joint shear capacity or for beam-column joint modeling purposes, which can be practically used by the design engineers.

摘要

强度等级评估方法是一种能力分析程序，可用于识别在地震或风荷载等横向作用下钢筋混凝土 (RC) 框架建筑物内可能发生的失效顺序。以前关于该方法的出版物主要集中于将该方法应用于 ( a ) 脆弱的 RC 梁柱接头，没有任何接头抗剪钢筋，其中主拉应力被认为是关键的，(b) 现代 RC 梁柱接头与接头抗剪加固，极端主压缩应力被认为是关键的。在本文中，现代 RC 梁柱节点（在节点中有横向钢筋）的节点抗剪承载力表示被概括为包括两个关键组件：主拉伸应力和主压缩应力。使用强度等级评估，研究表明可以将联合剪切能力表示为类似于柱的 NM相互作用的NM相互作用包络线。由此产生的联合抗剪能力NM使用包含 22 个外部和 22 个内部 RC 梁柱接头测试的数据库验证了相互作用概念，其接头核心处有接头抗剪加固，导致测试中的接头剪切失效。考虑到轴向载荷水平对钢筋混凝土梁柱节点预期性能的重要性，所提出的概念可用于节点抗剪能力的一般评估或梁柱节点建模目的，可在设计中实际使用工程师。