huangyhg

camber-length ratio
if girder got camber 2" how much that will be change lenght of the girder.
how to calculate?
assume the centerline length along the arc stays constant. with a small camber, the change in length should be fairly negligible.
example: with a 14,400" rolling radius and a 480" long beam, i get a 2" camber and a change in length due to curvature of 0.022".
how did you come up with 14400" for the radius? i get r=1200". anyway, i agree the length change is megligible. besides, once it is installed it will straighten out somewhat.
kxa,
one way is to use pythagorean's theorem: radius²=(½ span)²+(radius-camber)² this reduces to radius=[¼span²+camber²]/[2camber].
the arc length = 2radius*asin(½span/r)

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