A neighbor has a rather large creek going thru his property and while most of the time he can ford the creek at times that is not possible. The water reached 13' on two occasions this spring.
He wanted a bridge for foot trafic or ATVs and bought a stack of trusses from a Wal-Mart that was being torn down.
We had a very wet spring this year and he marked the high water mark on trees. He wanted the bottom of the main span to be 12" above that mark.
We put in concrete abutments 80' apart and put in an 8' long section of the truss in each abutment that we could then weld each section to. We had to go to 8' deep to find good material for a base for the concrete.
The bridge raises 3' from the abutment to a 40' main span then back down to the other abutment. Each span is 100' long ( hard to place as the trees are only 55' apart. ) We placed 3 spans 36" apart then welded X bracing to transfer any load to all spans ( much like the X bracing in the floor joist of a house )
Hopefully we will get the decking on this week with hand rails strong enough to keep a golf cart where it belongs. We are putting post at each end to allow foot trafic only that will have to be unlocked for ATVs as we intend that to be a rare occurance.
I had about 62 hours of welding to get the joints to be stronger than the spans they are connecting.
Here is one of the abutments showing where I welded the spans to it.
A view of the spans showing the rise and fall and some of the trees, we left as many trees as possible.
Just three long ribbons right now. Many more X braces to go before the deck.
Another view of the span from the other end. I will get pictures and post after completion - - -two or more weeks as I'm just working on this evenings after the other work is done.
The hardest part of this was the trusses were anywhere from 22" to 28" high and I had to make the tops match for the decking and also get the attachment points at the bottoms to match as well. If you look at the first photo the attachment points going to the abutments are all different to make the decking work right. One way to keep my brain working - - - In testing I chained the top of the center span to a backhoe and lifted the hoe off the ground with only 1/2" deflection - - - and it will get stronger as I get the X braces in and decking installed. The hand rails will be constructed to add strength as well.
Yes I know it is way over built for a walk bridge but that is as it should be!
No I do not intend to see cattle or horses cross!
He wanted a bridge for foot trafic or ATVs and bought a stack of trusses from a Wal-Mart that was being torn down.
We had a very wet spring this year and he marked the high water mark on trees. He wanted the bottom of the main span to be 12" above that mark.
We put in concrete abutments 80' apart and put in an 8' long section of the truss in each abutment that we could then weld each section to. We had to go to 8' deep to find good material for a base for the concrete.
The bridge raises 3' from the abutment to a 40' main span then back down to the other abutment. Each span is 100' long ( hard to place as the trees are only 55' apart. ) We placed 3 spans 36" apart then welded X bracing to transfer any load to all spans ( much like the X bracing in the floor joist of a house )
Hopefully we will get the decking on this week with hand rails strong enough to keep a golf cart where it belongs. We are putting post at each end to allow foot trafic only that will have to be unlocked for ATVs as we intend that to be a rare occurance.
I had about 62 hours of welding to get the joints to be stronger than the spans they are connecting.
Here is one of the abutments showing where I welded the spans to it.
A view of the spans showing the rise and fall and some of the trees, we left as many trees as possible.
Just three long ribbons right now. Many more X braces to go before the deck.
Another view of the span from the other end. I will get pictures and post after completion - - -two or more weeks as I'm just working on this evenings after the other work is done.
The hardest part of this was the trusses were anywhere from 22" to 28" high and I had to make the tops match for the decking and also get the attachment points at the bottoms to match as well. If you look at the first photo the attachment points going to the abutments are all different to make the decking work right. One way to keep my brain working - - - In testing I chained the top of the center span to a backhoe and lifted the hoe off the ground with only 1/2" deflection - - - and it will get stronger as I get the X braces in and decking installed. The hand rails will be constructed to add strength as well.
Yes I know it is way over built for a walk bridge but that is as it should be!
No I do not intend to see cattle or horses cross!
