Finally built a bridge

   / Finally built a bridge #12  
Can you say picture perfect?
 
   / Finally built a bridge #13  
Rob,

Looks very nice.

I noticed a few things in your pictures, and even though I don't really have any fear that it will fail, the life of it might be increased with a few changes. Since it's not a daily, high traffic type of struture, I could also be totally off base. If so, I apologize.

The beams are held in place with two bolts. That means that each bolt is carrying 50% of the load. I would add two more bolts and maybe even some Simpson Hangers. Spreading out the load and relying less on those two bolts would take allot of strain off of the wood.

How did you install the posts? A 6x6 is pretty sturdy and plenty strong enough for your loads, but the height of them above grade, especially in the middle, gives me some concern for racking. Adding some cross "X" bracing in both directions would stiffen it up, which you might not even notice right now, but will add years to the overall integrity and strength of the structure.

Eddie
 
   / Finally built a bridge #14  
.......
The beams are held in place with two bolts. That means that each bolt is carrying 50% of the load. I would add two more bolts and maybe even some Simpson Hangers. Spreading out the load and relying less on those two bolts would take allot of strain off of the wood..........

This is what I was referring to in post #8, Another approach is to notch the top of the post so that each beam sits on a shoulder of the post. I'm sure it is plenty strong for the intended use, as is.

Frequently decks are built with the same design, though nails may be used instead of bolts. New home owner has the whole extended family out on the deck to show it off and over she goes.
 
   / Finally built a bridge #15  
Looks good!!! :)
 
   / Finally built a bridge #16  
Nice job. Looks like it belongs there.

What did you use to treat the posts below the soil line? I can see from pic #1 that they are "painted" or "dipped" in something...
 
   / Finally built a bridge #17  
make shure you put some riprap upstream of the posts otherwise they will scour quickly.
 
   / Finally built a bridge
  • Thread Starter
#18  
Thanks for the interest, compliments and suggestions.

The beams are held in place with two bolts. That means that each bolt is carrying 50% of the load. I would add two more bolts and maybe even some Simpson Hangers. Spreading out the load and relying less on those two bolts would take allot of strain off of the wood.

How did you install the posts? A 6x6 is pretty sturdy and plenty strong enough for your loads, but the height of them above grade, especially in the middle, gives me some concern for racking. Adding some cross "X" bracing in both directions would stiffen it up, which you might not even notice right now, but will add years to the overall integrity and strength of the structure.
Eddie
I thought about using hangers but couldn't find any that would work with the way I bolted the beams to the 6x6's. I guess I could attach some 2x stock below each beam to provide some additional support.

The posts are sunk 3 feet and backfilled with concrete. I may add cross bracing but it seems very sturdy so far. If you look closely at the 3rd picture you can see where I left the 6x6's higher than the beams. That way the outside joists rest on the beams and are bolted to a post. That may take some pressure off of the beams.

This is what I was referring to in post #8, Another approach is to notch the top of the post so that each beam sits on a shoulder of the post.
I thought about that but leveling and aligning the beams was easier by bolting them to the posts. This way I was also able to bolt the outside joists to the posts.

What did you use to treat the posts below the soil line? I can see from pic #1 that they are "painted" or "dipped" in something...
Good eye, Nate. I used a copper based wood preservative on the lower half of the posts. I figured it was cheap insurance.

make shure you put some riprap upstream of the posts otherwise they will scour quickly.
I started to use field stones for rip rap on the creek bank and around the middle posts. The posts on either end of the bridge never see water.
 
   / Finally built a bridge #19  
Most engineered wood bridges have cross bracing on the upright supports. This would help your nice looking bridge in sturtural support and preserve it for many extra years. 2x's attachhed to uprights very good idea to releave strain on the bolts.
 
   / Finally built a bridge #20  
Here's a small walk bridge I build for my mother's brook side flower beds. I got to use the tractor to carry it from my house to hers (about 3/4 mile). I wish I could have used the tractor to build the rock abbutments....

In the summer both banks along the brook explode with blooms.


Dean
 

Attachments

  • IMG_0590.jpg
    IMG_0590.jpg
    1 MB · Views: 497
  • IMG_0596.jpg
    IMG_0596.jpg
    1 MB · Views: 630

Tractor & Equipment Auctions

12-Wheel Pneumatic Pull-Behind Asphalt Compactor (A49461)
12-Wheel Pneumatic...
New/Unused 2025 CFG MX15RX Mini Excavator (A48837)
New/Unused 2025...
2022 Kobelco SK85CS-7 Excavator (A48837)
2022 Kobelco...
2020 Kubota SVL95-2S Track Loader (A50490)
2020 Kubota...
2017 Taylor-Dunn BO24836 36V Electric Utility Cart (A49346)
2017 Taylor-Dunn...
2011 Jeep Grand Cherokee Overland 4x4 SUV (A48082)
2011 Jeep Grand...
 
Top