Steel U Frame Footbridge
Steel U Frame Footbridge
(OP)
Hi
I have designed a U frame footbridge.The fabricator has proposed to split the bridge in 3 section at cross members level. The cross members are 120x120x8mm SHS.The design loading on cross members are:-
Moment 20kN.m
Shear 20kN
Tension 22kN
The fabricator proposal is to use a plate 25mm thk with 4 nos of M24bolts for connecting the cross members.He is recommending to use 6mm fillet weld on 3 sides of the SHS section and one side full penetration Butt weld.
The required length for weld is 140mm.Is it correct to assume that the tension load of 189kN will be share by sides of the weld.
Any help would be great.
I have designed a U frame footbridge.The fabricator has proposed to split the bridge in 3 section at cross members level. The cross members are 120x120x8mm SHS.The design loading on cross members are:-
Moment 20kN.m
Shear 20kN
Tension 22kN
The fabricator proposal is to use a plate 25mm thk with 4 nos of M24bolts for connecting the cross members.He is recommending to use 6mm fillet weld on 3 sides of the SHS section and one side full penetration Butt weld.
The required length for weld is 140mm.Is it correct to assume that the tension load of 189kN will be share by sides of the weld.
Any help would be great.





RE: Steel U Frame Footbridge
Also, prying action by the bolts means also lever action at the fillet welds and transverse flexure for the butt weld (in sections perpendicular to the welds at each side), compounded with tension. In the case of the butt weld you may say well this is just more on one side, less another, plasticity will care. But in fillet welds it is simply additional tensile force. Care of this additional stresses will add to the required dimension of weld. I would be conservative as is proper when dealing with tensile members, more if not redundant.
RE: Steel U Frame Footbridge
Ishvaaag seems to understand your connection query, but I don't. A sketch would help.
RE: Steel U Frame Footbridge