How Would You Fix This Bridge?

[Mcdust]

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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[Mcdust]

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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My brother had a rail car over a creek entering his cranberry bog and it worked great

 

[Fxfymn413]

I would approach the solar farm folks and ask them if they want access to their panels through your bridge. If it makes their life easier they may bite and the cost to fix the bridge is probably a rounding error for them.

 

[bdhsfz6]

This is what I was going to suggest although my suggestion would be to make it 10ft x 10ft and put it over the top of the existing then remove the pipe and dirt underneath.

A great idea, but way beyond our means. It would also get the DEP involved and require modifying the easement we have through private property.

 

[bdhsfz6]

I would approach the solar farm folks and ask them if they want access to their panels through your bridge. If it makes their life easier they may bite and the cost to fix the bridge is probably a rounding error for them.

A definite possibility, but the solar farm hasn't received final approval and may be years in the future. Also, the access road to the solar farm runs off a township road a quarter mile away. Certainly something to consider though.

 

[WinterDeere]

Is the newer 5' sleeve failing, or just the original 6' pipe? Any chance to pull another 5' sleeve into the opposite end, to an insertion depth that butts up against the end of that prior 5' sleeve?

Obviously easier said than done, but shouldn't be terribly difficult if you clean out the old 6' pipe of any debris, and then you could cement the new sleeve in place by forming out the open end, to lock everything in place.

 

[rumwrks]

One thing I learned from watching the high water flow through the two 5' concrete culverts on the creek behind our place is that once you add flow restrictions you have to WAY over size things due to various forms of flow restriction. I've seen the tailwater out of them be at not much more than half full when it's already topping the road over them due to inlet restrictions/friction. I found the disparity to be real interesting and did a little reading and it's a significand design challenge. Bridges can have similar problems once you hit peak flows if there are restrictive abutments, etc.. but in general you need less slack than you do with a culvert system.

In light of that I would add that if you can pull the culvert and put in a bridge that would have a lot less flow restriction overall and might be easier to size/engineer the thing.. especially something prebuilt like one of the railway flatcars (I see those for $10-15k BUT you'd also need to built abutments, etc.. so the final total cost would be quite a bit more .. but it'd drop in pretty fast anyway).

I'd also be a bit wary of what would happen moving from a 6' to a 5' opening by sleeving it.. you already have overtopping problems and IMHO (I'm not a hydrologist.. I just like looking at the creek in the rain and observed some things..) that could make that a lot worse.

 

[ruffdog]

The stream (Navajo Creek) averages around 8' wide and 1 - 2' deep. The flow varies with rainfall. During high water events, the 6' pipe runs full.

What you can't see in the picture is, the bridge is sloped upward toward the left of the picture. The right side is only 2' above stream level. When the pipe obstructs the flow, the water backs up and flows over the roadway on the low (right) side. This acts as a "safety valve" and is likely why the bridge has lasted so long.

The most severe event happened during Hurricane Ivan in 2004:

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See pictures above ^^^If the culvert size was the main restriction, why is the level of the water AFTER the road nearly as high as the road? It seems to me that the entire area is low and gets flooded during large rains. To totally cure and prevent flooding of the road, a WAY bigger excavation, more culverts, and raising the road 2+feet would be needed. The OP has said that is not on the table......

 

[rumwrks]

See pictures above ^^^If the culvert size was the main restriction, why is the level of the water AFTER the road nearly as high as the road?

Yeah that's peak peak flow though.. I'm certainly not claiming that a bridge would solve this problem.. but going to a smaller culvert could make smaller floods a real problem when they aren't now.. and a bridge could make medium floods less of a problem in this regard than they are now.

I don't know how much variation there is in peak flows there (maybe they only get no rain or torrential rain so it actually is a binary problem.. but that would be unusual..). A bridge DOES come at a cost of different engineering difficulties as well in making sure it's properly anchored, etc.. cause they're going to have some over topping regardless.. nothing is free.

It's more a point that I think it would behove OP to get some actual engineering done because culvert flow properties are far from intuitive and maybe some of what's been proposed here would work well.. or maybe it would make things worse. I don't have enough data to be real certain. I think they're likely going to need a stamp to appease the powers that be regardless.

 

[chim]

The rail car or some pre-fabbed deck sounds attractive. Footers and foundations could be built back away from the creek so it wouldn't be disturbed. Maybe even have it high enough so it doesn't touch the existing road. Then sit back and let nature claim whatever it wants.

When we built here back in '90 we had to build a bridge for access (our driveway). The bore is 16 feet. I had an engineer design one that would support fire trucks. Long story but we built it on dry ground near the creek, then straightened the creek so it would flow through the bridge.

One picture shows the original creek in red and the new path with the bridge in yellow.

 

[bdhsfz6]

Is the newer 5' sleeve failing, or just the original 6' pipe? Any chance to pull another 5' sleeve into the opposite end, to an insertion depth that butts up against the end of that prior 5' sleeve?

Obviously easier said than done, but shouldn't be terribly difficult if you clean out the old 6' pipe of any debris, and then you could cement the new sleeve in place by forming out the open end, to lock everything in place.

The newer upstream 5' pipe is in pretty good shape. We considered the insertion idea but the 6' pipe is deformed to the point where there isn't enough clearance. The only thing holding the old pipe together is all the piecemeal concrete we've poured around it over the years. A few more pours, like the one I just posted, and the pipe will be completely encased. That may ultimately keep it from collapsing, but the whole mass is being undermined and is slowly sinking.

 

[bdhsfz6]

The rail car or some pre-fabbed deck sounds attractive. Footers and foundations could be built back away from the creek so it wouldn't be disturbed. Maybe even have it high enough so it doesn't touch the existing road. Then sit back and let nature claim whatever it wants.

When we built here back in '90 we had to build a bridge for access (our driveway). The bore is 16 feet. I had an engineer design one that would support fire trucks. Long story but we built it on dry ground near the creek, then straightened the creek so it would flow through the bridge.

One picture shows the original creek in red and the new path with the bridge in yellow.

This is the idea we are pursuing now. One of the landowners, who is a contractor, is building a house and has a vested interest in the bridge. He is looking into possibilities & costs associated with using precast concrete beams. At least we have some hope with him in the mix.

 

[dodge man]

While I did mostly surveying I worked for a civil engineering company my entire career. We did a lot of work for small towns without much if any money. No money no work for us. That meant a large part of our work was getting grants and other funding sources. Like already suggested look for some funding sources. The key is to find the person/agency that knows where to look for funding. It could be considered a life safety issue.

A lot of bridges are built around here with precast deck beams but they are built on poured in place abutments that also have piles driven deeply into the ground under them. That equals $$$$.

 

[Brianczaw]

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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We have a similar situation but not that big. We have a 30 foot 48” metal pipe that is collapsing. Were are going to slide a 36” poly pipe through. When the pipe finally does collapse, we’ll just fill in and replace that little bit of crossing.

 

[Fuddyduddy1952]

If it were me I'd push/pull an 18" corrigated plastic pipe though it and call it a day. Industrial pipe is easy to get and isn't too expensive. It also comes in 15' sections. Couple 2 and drop them in. Set up some rocks/anchors on the output side to keep it from getting pushed through and the same on the input side to help protect the gap there. Fill the road cracks with a course sand such as "grits" from the gravel pit. You want sand so it will percolate down into the crack to fill it deep. Just keep adding sand every now and then until it stops going in. Then if at some point later you want, you can repair the top 4" of hot top with some bags of patch and it should be good to go for a long time.

18" waaaaayyyy to small, especially after downpours.

 

[johnnylee1945]

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

Suggestion:
About DIY Bridge — How It Works | DIY Bridge

 

[WinterDeere]

I think everyone here is missing the point. This is nothing but a thinly veiled excuse to buy another boat.

 

[David in KY]

Suggestion:
About DIY Bridge — How It Works | DIY Bridge

Probably couldn't solve the OPs bridge issue (due to small load capacity), but what an awesome invention.

Thanks for sharing that Johnnylee1945 !!

 

[Marauder]

Cured-In-Place Pipe (CIPP) – Tischbein Co. Inc.

www.tischbeincoinc.com

Maybe?

 

[jyoutz]

Cured-In-Place Pipe (CIPP) – Tischbein Co. Inc.

www.tischbeincoinc.com

Maybe?

I doubt that they have that product in 6’ diameter size.