Arched beam radius

tee2

I am building a 24' span bridge and will be building an arched laminated beam. The beam will have a 27' radius for the arch, my question is, my hand rail which will be 40" high and arched, what would be the correct radius to use when making my rail? Would it be 27' plus the 40" to equal 30.5'? I am making a large jig to construct the beam and want to plan ahead for the various radius' I'll need to construct.

47_47

40"/12=3.333'
27+3.333=30.333'
30'4" radius

I built my 20' span with 12" grouted concrete blocks, used a 30" poly pipe, tied the walls with ss cables and back filled with stone. I can drive my pick up over it.

I'd also consider lighting this bridge.

Added: I sure hope you get a permit and an engineers approval for this design.

__________________
What we've got here is... failure to communicate. Some men you just can't reach. So you get what we had here last week, which is the way he wants it... well, he gets it.

tee2

Great, that's what I was thinking even though my math was off a little. The bridge is just a fancy garden bridge over a small creek that will only have limited foot traffic at best, it's more for decoration than anything so I wasn't planning on a permit.


Thanks for the help

Termite

Depending on where you live, there can actually be some big issues with building over creeks/waterways. In the city I work we have several creeks that feed a larger creek, and little bridges like you described require state permits and Corps of Engineers permits. With those two agencies involved, our city permit is required but rather insignificant. The State and the Corps are super-serious about this sort of thing, and it doesn't matter whether it is on private property or not.