建筑施工中,常因缺乏设计图中所要求的钢筋种类、级别或规格而需要用别的钢筋进行代换。钢筋代换时,一些施工人员往往只注意梁的正截面受弯承载力,而忽视其斜截面受剪承载力,致使代换后梁的受剪承载力不足,留下事故隐患。图1所示为某工程设计的简支梁。原设计底筋采用4 18,即2 18 In the construction of a building, it is often necessary to replace it with other steel bars because of the lack of the types, grades or specifications of steel bars required in the design drawings. In the replacement of steel bars, some construction workers often only pay attention to the bending capacity of the normal section of the beam, and ignore the shear bearing capacity of the oblique section, resulting in insufficient shear capacity of the beam after replacement, leaving hidden accidents. Figure 1 shows a simple beam designed for an engineering project. The original design of the bottom ribs used 4 18, ie 2 18