一、问题的提出众所周知,设计半穿式钢梁时,因桁梁上弦杆或板梁上翼缘受压,而两片主梁之间无顶面联结系,故必须考虑上弦杆或上翼缘在主梁平面外横向的稳定性,即求其自由长度αL。为此《桥规》附录十二依据文献给出了β值,在0～1000之间时的系数α值表。 First, the problem is raised As we all know, the design of half-penetrated steel beams, the truss beams or slab beams on the flange compression, and no connection between the two beams of the top surface, it must consider the winding rod or the upper flange in the The horizontal stability of the main girder out of plane, that is, to find its free length αL. To this end, “Bridge Regulations” Appendix 12 according to the literature is given β value, the coefficient α value table between 0 to 1000.