31' Bridge across Creek

[deanfitz]

I have been working up plans for a bridge on my property and have gained some excellent ideas here on Tractorbynet & I thank everyone.
What I've decided to do is go with steel I beams 39' L x 12"H x 10"W @ 53lbs a foot. The span will be 31' with the remaining ends of beams embedded in the cement abutments. These footers will be 12'Wide x 8'Deep x 4' Thick. There will a center angle embedded along with 6 cross angle supports 5'2" apart. Still undecided on the cross timbers on top. But likely will be "Rough Cut Treated" 4x12's. I plan to begin construction in March 2011, should have everything in order by then. When the weather lets us, we'll start.

Here is a picture of the Overhead View & Endview of the cement footers.
http://i785.photobucket.com/albums/yy139/deanfitz/BridgeBeamsEmbedded-1.jpg

Cheers, Dean

 

[Treemonkey1000]

Sounds like a fun project. Something that big you don't think the Authorities will come along and give you some grief? Around here it is hard to widen a ditch without getting in trouble.

 

[deanfitz]

Its in the wilderness, the Game Wardens will love that they will now have a way to get back to the river ha ha. Its on my private property in La. and local clerk of court said there is no restriction on private crossings.

 

[LD1]

In your other post, you mentioned the bridge guy said the larger beams would be worth the extra money, did he happen to give you an Idea at all of what the load capacity would be??

I can calculate it this evening and let you know.

Other than that I just wanted to post to this "new" thread so it would subscribe me to it and I can follow along.

 

[deanfitz]

I never did Beamboy to work, but Robbie said these beams will hold a min. of 10,000lbs at center. Also, putting the beams all the way across the footer will add strength.

 

[deanfitz]

Here is the location as seen from Google Earth. Its .45 miles from river. I could end up with a sandy bottom hole.
http://i785.photobucket.com/albums/yy139/deanfitz/BridgeLocation.jpg

 

[futuresweets10]

Been following this in the other thread and im interested to see how it comes out.

 

[deanfitz]

Really just planning at the moment. Next step to dig a 8' post hole to see if it will fill with water.

 

[hobie]

Gorgeous piece of property. I look forward to following this one too. Hope you take lots of pics for us!

 

[LD1]

I have been working up plans for a bridge on my property and have gained some excellent ideas here on Tractorbynet & I thank everyone.
What I've decided to do is go with steel I beams 39' L x 12"H x 10"W @ 53lbs a foot. The span will be 31' with the remaining ends of beams embedded in the cement abutments. These footers will be 12'Wide x 8'Deep x 4' Thick. There will a center angle embedded along with 6 cross angle supports 5'2" apart. Still undecided on the cross timbers on top. But likely will be "Rough Cut Treated" 4x12's. I plan to begin construction in March 2011, should have everything in order by then. When the weather lets us, we'll start.

Here is a picture of the Overhead View & Endview of the cement footers.
http://i785.photobucket.com/albums/yy139/deanfitz/BridgeBeamsEmbedded-1.jpg

Cheers, Dean

Well there is no W12 x 53 beam made. They go from 40lb to 50lb to 72lb. (at least in the beam boy lists) So I used the 50lbf beam.

With a 31' span, you are allowed a deflection of 1.03"

Using the preciously stated 60lb per foot distributed load for the timbers. (I didn't factor your cross peices but I doubt they will add up to more than 500lbs for the entire span which would only add 8 Lb per ft.) A 10000 lb point load in the middle of the beam would net a deflection of 1.01". So he was right and yes it will handle it. That would give the bridge a rating of around 20k max.

Some more food for thought:
Why not price a W18 x 35 I-beam. Since steel is usually priced according to weight they would be cheaper. And they would also be stronger. Each beam would be able to carry just shy of 15000 LB in the center. Making the bridge safe to almost 30k. Being lighter, they may also be easier to set(not as big of equip. required). @39' long they would weigh 1365 lbs instead of 1950 lbs.