The Research Of 128m Simply Supported Steel Truss Girder Of Jiangjundu Yellow River Bridge

This paper mainly focus on the design and calculation of the simply supported steel truss girder,with the span of 128 m and the engineering background of Jiangjundu Yellow River Bridge.Midas Civil was used to establish the finite model,the specific process is as follows:Firstly,the overall concept of design should be processed,which includes the design of the main girder,node design,the design of the deck system,the design of the coupling system and portal frame design etc.After the design,Midas is used to build the model of the girder according to the preliminary section size and the materials. Then determine the loads,combine them,analyse the force and make sure the control interforce of each bar,namely,the maximum or the minimum axial force. The precamber is simulated by heating model.Checking each bar based on the control interforce. The formula and the check projects vary on each member’s location.Since the center of upper chord is compression member, the cross section stiffness, local stability and global stability need to be checked; Bottom chord is tension member, so the calculation of strength, stiffness and fatigue problems need to be considered; The diagonal member of both ends belongs to bending bar, therefore stiffness, strength and overall stability should be checked; The stress of the diagonal is more complicated,where stiffness, strength and stability of the bar and fatigue strength should be calculated.Each part of the structure and the integrity is accord with the corresponding regulations,proving that the design is accurate and reasonable.Finally, the design work of the detailed structure is done, which includes the design of ballast retaining wall,anti-drop longitudinal beam, drainage and ridge inspection equipment.