1.桁架式主梁的构造及产生变形的原因桁架式主梁的一种构造形式是承轨梁以Ⅰ形梁(单腹板)作为主桁架(图1a),副桁架由型钢构成(图1b)。桁架式主梁就由这两个垂直的主、副桁架组成。在主、副桁架之间,上下,用型钢连接形成水平桁架,组成长 1. Trussed girder structure and the reasons for the deformation Trussed girder structure is a kind of girder girder with I-beam (single web) as the main truss (Figure 1a), deputy truss by the steel structure (Figure 1b). Trussed girder by the two vertical main and auxiliary truss. Between the main and auxiliary trusses, the upper and lower trusses are connected by steel bars to form horizontal trusses, with long formations