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Steel Canopy 2
- Thread starter Murali27
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- #2
6m is not that far, I have done 9m cantilevers before.
If the cantilever is rigid enough then I would not expect vibration to be an issue.
Precamber it, and design it for a deflection of L/250 to ensure the dead load sag is not visible.
You also may need to check the rotation due to the supporting structure.
If the cantilever is rigid enough then I would not expect vibration to be an issue.
Precamber it, and design it for a deflection of L/250 to ensure the dead load sag is not visible.
You also may need to check the rotation due to the supporting structure.
- Thread starter
- #3
Thanks for your reply
The cantilever (probably tapered hollow section) support is attached to a concrete beam which is running over columns.
As you said, it is better to attach on columns, if sections are ok for architect.
Design gust wind speed is around 48 m/s at this site. Vibration and reponse factor could be checked with assumed frequency range for winds. I am just to feel the numbers, hope that it is not critical
The cantilever (probably tapered hollow section) support is attached to a concrete beam which is running over columns.
As you said, it is better to attach on columns, if sections are ok for architect.
Design gust wind speed is around 48 m/s at this site. Vibration and reponse factor could be checked with assumed frequency range for winds. I am just to feel the numbers, hope that it is not critical
The critical item for this will be the connection into the concrete frame.
Assuming this is a new building, then it could be an embedded plate.
Dont forget the check the beams for torsion and the frames for additional sway from the wind on the canopy.
Assuming this is a new building, then it could be an embedded plate.
Dont forget the check the beams for torsion and the frames for additional sway from the wind on the canopy.
- Thread starter
- #5
20mm seems high, are you sure this is not for the whole building?
Embedded plates are usually solid plates with rebar welded to the back of them, they are embedded into the concrete and then the canopy is welded to them. This is a fairly common practice with precast concrete (PC), so you should look at publications on PC for guidance.
Embedded plates are usually solid plates with rebar welded to the back of them, they are embedded into the concrete and then the canopy is welded to them. This is a fairly common practice with precast concrete (PC), so you should look at publications on PC for guidance.
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- #7
Agree with csd72 that your columns should not shorten 20mm at the ground floor level. This is probably the shortening over the height of the column. There should be no need for slotted holes or other means of adjustment. At any rate, I would think that the canopy would be erected late in the schedule.
As well as embedded plates, you could consider casting in anchor bolts to develop the bending moments and shear from the cantilever. Either way, be sure to fully develop the hollow section cantilever member to the end plate. Full strength welds will require backing strips.
As well as embedded plates, you could consider casting in anchor bolts to develop the bending moments and shear from the cantilever. Either way, be sure to fully develop the hollow section cantilever member to the end plate. Full strength welds will require backing strips.
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