How Would You Fix This Bridge?

[bdhsfz6]

The bridge was built in 1913 by dumping fill over a 6' diameter steel pipe, which is rotting away. The span over the pipe is around 20' to get to solid ground on either side. There is 36" of fill on top of the pipe, topped with 6" of modified gravel. Water is running beside the pipe and undermining what's left of it. As a result, the downstream side (left in pics 2 & 3), is subsiding. The aerial photo is north up orientation and the stream flow is top to bottom.

It's a private road, used by only a few property owners with limited resources. Contractor estimates to replace it with a 6' poly pipe are upward of $50K, which we can't afford. The price is elevated by DEP regulations which require the stream to be diverted during construction. The only way to do this is with large pumps. Stream flow and environmental impact studies prepared by a certified engineer are also required. Construction is made more difficult by overhead transmission lines.

The "cheap" fixes we've been looking at include using flatbed rail cars to span the pipe, or perhaps a 20' reinforced concrete slab. To avoid DEP regulations, anything we do can't disturb the stream.

Any ideas or suggestions would be greatly appreciated.

 

[Topzide]

Dig in abutments ti then span with rail cars or a reinforced concrete slab for a bridge. That way, you're not disturbing the stream flow. You'll need the abutments to keep the stream from eroding the banks of whatever bridge style you decide on. Now the DEP knows there is an issue, they'll keep a watch on you. Good luck.

 

[JJT]

Can you sleeve it with a 5' culvert pipe and grout the gap between the new culvert pipe and the old steel pipe?

 

[dodge man]

I assume this is a private drive? If you build a slab you need some kind of abutment to support it, maybe not with a rail car. I worked in the engineering world for nearly 40 years and stupid regulations can get ridiculous.

 

[airbiscuit]

Can you add pics looking through the culvert?

 

[LouNY]

The rail flat car would be nice, just set it on a couple of concrete slabs.
Or a pair of tractor trailer flat beds set side by side for a 16 ft wide bridge.

 

[Rustyiron]

How close to town and the "eyes" of the dirt police?

 

[Rustyiron]

That power line, do they occasionally access that line on your side of the creek. It crosses it but for how long? I'm guessing that your to the left in the overhead view.
(They might participate in this venture)

 

[RayIN]

Build a new box-type culvert beside the old one. When completed divert the creek to the new culvert. Box culverts have concrete wings and a concrete box(no bottom) for water flow. There is a box culvert in front of my house in the county road that's been there since the 1940's. I've watched fully-loaded tri-axle dump trucks drive over that culvert several times a day each spring and it's not been damaged yet.

A box culvert looks like a bridge and is often mistaken as such. This company builds pre-cast box culverts, but looking at them is a good visual aid to help understand how the look. Their design with a separate top is what I tried to describe, but turned upside down..

https://precast.org/theprecastshow/wp-content/uploads/sites/5/CP1-Box-Culvert-Design-Detailing_FINAL.pdf

 

[jigs_n_fixtures]

Build a new box-type culvert beside the old one. When completed divert the creek to the new culvert. Box culverts have concrete wings and a concrete box(no bottom) for water flow. There is a box culvert in front of my house in the county road that's been there since the 1940's. I've watched fully-loaded tri-axle dump trucks drive over that culvert several times a day each spring and it's not been damaged yet.

A box culvert looks like a bridge and is often mistaken as such. This company builds pre-cast box culverts, but looking at them is a good visual aid to help understand how the look. Their design with a separate top is what I tried to describe, but turned upside down..

https://precast.org/theprecastshow/wp-content/uploads/sites/5/CP1-Box-Culvert-Design-Detailing_FINAL.pdf

If you want to build a box culvert in place, check to see if your state highway department has the design available as a standard plan. Haven't checked in a while but Nevada, Idaho, and California used to have tem as standard plans available for free download. The Nevada ones have table which tell you how much concrete, and reinforcing steel is required.

 

[rScotty]

OK, you asked for suggestions. Here goes:
That's a nice project. BTW, & congratulations on getting 100+ years on the original.
Concrete box culverts are very nice, but spendy. But do that if you can afford it. Steel culvert is way less expensive, & 100 years is reasonable. Steel culvert quality varies a lot. Some of the better is heavier gauge and coated.

Just guessing based on our area, these 4 items listed below on a rural job, on a private road to private land could cost as little as $5K each or as much as twice that. Allow the same $5K for overruns and so you are at $25K. min. here. Not bad compared to $50K, and frankly the $50K you were originally estimated too far isn't out of line if this road sees tonnage or has to be rated in any special way - for fire trucks for example.

1. I would call around and see if I could get an older professional civil engineer on my side. His stamp will be needed, and he can design alternatives for some regulations. He has probably dozens of this type repair & has stream data and local knowledge.

2. Ask around to see if anyone sleeves old culverts. A 5 foot sleeving for existing 6 foot pipe can be considered a temporary internal diversion since it prevents the construction muck from being carried downstreanm - which from your photos is what is happening with the undermining going on right now. The civil engineer will need to draw up plans for the DEP so that the sleeving is an acceptable temporary bypass.

3. Expect to put in a pair of new six foot culverts - one on each side of the central sleeved pipe...or whatever fits. It's good practice to ALWAYS put in two or more same size culverts side by side - each one sized for full flow. Climate change means local flooding, so an even better idea is to have one or more offset above the others in case of flood debris plugging the lowers. This is the time to do this job because most local codes haven't changed as much as the climate will....yet.

4. Plan for a large excavator. Looks like a one day job but allow for two. The excavator should already have knowledge/permits for working around power lines.
Tell him he may need to do some compaction around and between culverts. He will know that anyway..
You could make back some of your cost if the culverts displace enough decent dirt to avoid having to bring in fill. But you won't know that until you dig.

5. Put the guard rails back to code.

Good luck,
rScotty

 

[bdhsfz6]

How close to town and the "eyes" of the dirt police?

Very close. The main problem is, it can be seen from the main highway.

 

[bdhsfz6]

Can you add pics looking through the culvert?

Unfortunately, The banks are too overgrown to get down in there.

 

[bdhsfz6]

That power line, do they occasionally access that line on your side of the creek. It crosses it but for how long? I'm guessing that your to the left in the overhead view.
(They might participate in this venture)

Yes, Power company vehicles do use the bridge, so that's a possibility. Unfortunately, the bridge would have to become impassible before that would happen.

 

[bdhsfz6]

Can you sleeve it with a 5' culvert pipe and grout the gap between the new culvert pipe and the old steel pipe?

We looked into this a few years ago. In 1976, a 5' diameter pipe was partially inserted into the old 6' pipe on the upstream side in order to widen the road. We would have to use a 4' sleeve, which would be too small for the stream flow. We would also have the DEP on our back for sure if we tried it.

 

[bdhsfz6]

Thanks for all the suggestions so far guys but keep in mind, it's two 80 year old men with some equipment and a very limited budget who wind up doing all the maintenance work.

The two of us own the largest pieces of land and the most valuable houses. We're the only ones who seem to care about property values. Most of the other properties that are accessed via the bridge are summer homes or absentee landlords who rent. Obviously, we don't get much support.

Sad to say, even though we love it here, we are considering the idea of moving elsewhere. In the long run, it might be the cheapest way out. Unfortunately, the deteriorating bridge has affected our resale value.

Right now, we're stuck with putting band aids on the bridge in the hopes it will last another 10 or 15 years. After that, it will be someone else's problem.

 

[Topzide]

What about a surplus bridge to go right over the top?

Bailey Bridges, Inc.

Search military bridges. Might be another option.

Could also look for forestry bridges that are used in logging for creek crossings.

Just a couple of other options to look at.

 

[Engineer42]

The bridge was built in 1913 by dumping fill over a 6' diameter steel pipe, which is rotting away. The span over the pipe is around 20' to get to solid ground on either side. There is 36" of fill on top of the pipe, topped with 6" of modified gravel. Water is running beside the pipe and undermining what's left of it. As a result, the downstream side (left in pics 2 & 3), is subsiding. The aerial photo is north up orientation and the stream flow is top to bottom.

It's a private road, used by only a few property owners with limited resources. Contractor estimates to replace it with a 6' poly pipe are upward of $50K, which we can't afford. The price is elevated by DEP regulations which require the stream to be diverted during construction. The only way to do this is with large pumps. Stream flow and environmental impact studies prepared by a certified engineer are also required. Construction is made more difficult by overhead transmission lines.

The "cheap" fixes we've been looking at include using flatbed rail cars to span the pipe, or perhaps a 20' reinforced concrete slab. To avoid DEP regulations, anything we do can't disturb the stream.

Any ideas or suggestions would be greatly appreciated.

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If your contractor gave you a price of 50k, to r&r, with everything you've stated, that sounds cheap. Lining would be ideal, but you already explained how that won't work for you.

Who installed the guardrail? Is that private also?

 

[bdhsfz6]

If your contractor gave you a price of 50k, to r&r, with everything you've stated, that sounds cheap. Lining would be ideal, but you already explained how that won't work for you.

Who installed the guardrail? Is that private also?

We installed the guardrail ourselves. It was state surplus and we got it for cheap.

Yeah, that $50K estimate was a few years ago. Maybe double today.

 

[Jstpssng]

How wide is the stream, bank to bank upstream and downstream? Also how deep is the channel? Looking at your picture it appears that there is a fair amount of water going through, and the flow has been restricted at the bridge for quite some time. (113 years?)
While others mention regulations, I'd be more concerned with the new bridge blowing out. Paying to do it half assed twice is going to cost more than fixing it right once.
Concrete waste blocks are relatively cheap. Rent an excavator, go two blocks high if necessary and then you likely could go with the RR car. I've also seen them made with the steel from log truck trailers, and we trucked over them with 100,000 lb loads.