Hello,
I am trying to use LEAP Steel for a high skew steel bridge.
When checking the automatically generated the concrete deck self-weight, there is an issue that I do not understand.
The self weight of the concrete deck seems to be calculated with the skewed length between the girders, and not the perpendicular distance.
I checked the same 3-span bridge with and without skewed support and the concrete self-weight generated by the software are giving me different values, which does not make any sense to me since the bridges are the same width, so they should have the same overall self-weight on them. Has anyone been able to resolve this issue? There must be a setting that I am not indicating properly
Bridge 1 - Straight supports:
Perpendicular distance between girders: 6.5 ft
Skew: 0 degrees
Distance between girder (along skew): 6.5 ft (6.5ft / cos 0 deg)
Deck thickness: 7.0 in + 0.5 in sacrificial wearing surface + 2 in haunch.
LEAP generated self-weight of slab for an interior beam = 0.5685 kip/ft (150 pcf x 6.5 ft x 7 in/12 ft/in = 0.5688 kip/ft OK)
Bridge 2 - Skewed supports (same bridge (same design file but changed the skew)
Skew: 54 degrees
Distance between girder (along skew): 11.06 ft (6.5ft / cos 54 deg = 11.06 ft OK)
LEAP generated self-weight of slab for an interior beam = 0.9674 kip/ft (150 pcf x 11.06 ft (???) x 7 in/12 ft/in = 0.9678 kip/ft ????)
I do not understand why these two bridge do not have the same slab self-weight on them even though the overall surface of the deck will be the same. This ends up being a very significant difference and makes me think I am not modeling something properly.
Any input would be greatly appreciated. I would assume someone has gone through this already and has found the solution!
Thank you in advance
Emilie