Driveway bridge ??

[mike944]

Anyone ever dealt with a small bridge in their driveway?

I saw some property for sale, but the only "catch" is it needs a bridge to go over a brook. I don't even know who to call on this one. The brook is small, the bridge would maybe have to span 30' max. The property is obviously worth less, due to the no current access, but i'm trying to get a ballpark idea how much a small bridge would cost. I anticipate it being pretty expensive, (10-30K) but without even a ballpark estimate i could be off by a factor of 2 or more.

Anyone ever had to get a small bridge constructed, repaired, or replaced? How much? What kind of weight standards did they make you build it to?

 

[PAToyota]

Start by checking state and local regulations - even small bridges usually fall under DCNR, DEP, and other jurisdictions due to possible impacts on the waterway, flooding, and such. Meeting the regulation requirements can quickly raise the cost of even a simple bridge. The next issue is making it robust enough to handle larger vehicles. You may not think this is a problem until you try to get a moving van or other delivery truck to cross it and find that you end up being responsible for getting any items to the house from the other side of the bridge. I know of a case where someone built a house and bridge in such a situation and then ended up with all of their furniture being delivered to the shoulder of the road...

 

[mtwaterguy]

Be sure and check with your local fire dept. also. If they don't feel that your bridge is up to code they won't cross it. Could help out with your fire insurance.

 

[rsanter]

you said it was about a 30 ft span, but how deep is it?

a guy I knew had a creek going across his drive. it was only about 6-8 inches of water so a truck crossed no trouble and many cars as well. it was a great barrier to keep the unknowing out as many were afraid to cross it. I was a little timid the first time but after that it was not big.

bob

 

[Jay H 237]

Around here I've seen culverts buried under driveways to allow the stream to pass under it. If it's a wide stream then there may be a few of them placed side by side with fill inbetween and crushed rock for embankments around the culverts.

 

[Blue]

Saw a guy buy a used bridge for a project like this. Don't know where he got it.

If you plan to build on the property, make sure it's not a wetland.

 

[mike944]

thanks for the input guys.

I haven't started looking into regulatory stuff yet. That may become unmanagable.

I would want it to be capable of handling trucks, but i don't want to have to make it like it was designed for an expressway.

I don't have the depth, but i'll assume just driving across it is out.

Culverts are strongly discouraged in this area. I don't think it's even worth the hassle trying to get it approved.

I was looking at prefab bridges. there are actually quite a few people who make them. I need more details before i call them. (no wetlands to worry about, only the ones at the stream)

 

[swgray]

The U.S. Army Corps of Engineers will be involved at the mere mention of a structure over water.

Good luck with that.

BTDT

 

[Junkman]

I know someone that had a similar problem, and they used a flat bed 40' trailer to cross the stream. No permit was needed, since it wasn't considered a permanent structure. There is an old bridge that crosses a stream on my land, and it consists of two very heavy and long steel H beams, and has a 3" thick oak decking on it. No railings or any other "safety" devices. I have seen the water go over the top of it many times in the past 30 years, and it is still standing. At one time, they poured a concrete wall on either side of the stream and then laid the steel over the top edge of the walls. This is also in CT.

 

[Bear]

I have also seen flat bed rail cars used if the span is right.

Just looking at an ad @ 541-729-7593 & 541-998-6605 they maybe able to give info for your area.

 

[safetyfast]

There's lots of creeks around here and most of the bridges I've seen recently are steel culvert with concrete poured over them.

 

[SteveU]

thanks for the input guys.

I would want it to be capable of handling trucks, but i don't want to have to make it like it was designed for an expressway.

Culverts are strongly discouraged in this area. I don't think it's even worth the hassle trying to get it approved.

I was looking at prefab bridges. there are actually quite a few people who make them. I need more details before i call them. (no wetlands to worry about, only the ones at the stream)

Even though you don't have them on it all the time, if you ever want to do a project that includes pouring cement it will have to be built strong enough to drive a 70,000 lb cement truck over it. Hauling enough cement bags & mixing & pouring them by hand to do a driveway, foundation, shop floor, etc, is not something you want to do. Then there is the more common propane/fuel oil truck along with the UPS vehicles to think about. Make sure whatever you build or buy can handle these.

 

[Lloydthumper]

Ramp dug down and a ramp dug up and a 4x4 equals fun and no bridge.

 

[Firetrucks]

I have a bridge made with I-beams and 2" thick oak planks. The bridge has handled anything I have driven across it (remember I collect fire trucks).
As mentioned the semi flatbed is a good idea and have seen a couple in use, but you are limited by width. Most commercial drivers will not cross that bridge when they get to it (sorry couldn't resist). As mentioned they'll either drop the load on their side or return to the dock/base and make you come get whatever it is.

Attached is a picture of a 9 ton rig that the wrecker driver pulled out from under hurriedly because he was in a bad mood. The front of the rig dropped about a foot on one side to the bridge deck and it held. That's not me driving I was beside him saying @#$%$##@@ to the wrecker driver.

 

[Junkman]

If you think that one flat bed trailer is too narrow, put two side by side. No matter how big the truck, it can straddle the middle of the two.

 

[Bib Overalls]

If you are going to build on the other side your bridge will have to accomodate a loaded cement truck.

 

[Deltarat]

We had a creek to cross years ago that was about 40' across. We got a railroad boxcar for next to nothing. We cut the box off and used the flat car part. We crossed it with 75,000# loaded semi's with no trouble.That was 40 years ago and it is still as good as ever. With the decline of the railroad industry, you could probably find a flat car or box car cheap.

 

[boiler7904]

I'd call a local civil engineer and see what info they can give you on a possible permit path and an estimated cost.

As soon as you go the 4x4 and no bridge route, the creek will flood and you be stranded on one side or the other.

Culverts will pop out of the ground if you get enough water flowing around them. One of the projects I was on last year required installing a new 30' wide 6' diameter culvert across a ditch for access to a neighbor's driveway.

When 300 acres of ground gets 4" of rain in 8 hours, the storm runoff is impressive. It popped the culvert so that it was standing nearly vertical in his front yard. As soon as it was fixed, we got a similar rain and you guessed it, the culvert went vertical again.

 

[Rte66Charlie]

Ditto the above post about flatbed (semi) trailers and the post about putting two side by side - Since the norm now is 48' and 53' trailers, 40', 42', and 45' can be had for a song. Virtually all those old trailers were designed for 50,000 lbs in a 10ft span, so with two side by side you'd be set to handle any truck you could ever imagine crossing it!

 

[atch]

another option not specifically mentioned above:

a friend lives waaaay out at 40th & plum. his driveway is about a half mile long and crosses a small stream which sounds about the same size as the one you're contemplating. jack bought an old bridge that the county was going to demo and moved it to his property. this is one of the old one-lane jobs with structural beams on both sides about 6' high, but nothing overhead.

he then 'dozed out a path near the bridge that trucks, tractors, and such can cross without worrying about the load carrying capacity of the bridge. in effect the lower crossing is a ford. i have never looked closely enough to see if he poured any concrete at the ford. but if he had he would have what we call around here a "low-water bridge". he's had tractors, hay wagons, delivery trucks, concrete trucks, etc., cross the lower road without ever having to worry about how heavy they are.

 

[6768rogues]

I agree with Boiler. I would go to a local civil engineer and talk to him. He will know or be able to determine the legalities, flood plane, and be able to recommend or design a bridge suitable for the load and the soil properties. Sometimes it is worth getting some professional advice, and I think this is one of those times. When all is said and done, maybe you can place a couple of footers and have a prefab concrete box culvert installed at a reasonable cost.

 

[Sundowner]

bieng that I'm a bridge engineer, I can tell you that there are about 14 different ways to skin this cat. you will NEED To find a local engineer to look at the situation. depending on how **** your local and state DEP is, this could get expensive. Assuming they let you dog in the stream, the nthe cheapest and most logical solution will be a precast concrete box culvert. IF they don't let you dig in in the stream, then you're talking about driven piles or a concrete spread footing behind the bank and either steel or concrete beams spanning over top. If they let you get away with the box culvert, then you're looking at about $150/sf to build a bridge that's probably going to need to be about 15-18 feet wide. If you're looking at driving piles, and spanning over, then you're talking $230-$300/sf to get it done. These are REALLY rough numbers, and you may find that in your area you can get it done for significantly less.

And keep in mind that one it's built, it's YOUR bridge. you have to regularly maintain and inspect it to maks sure that it's safe.

 

[mike944]

Thanks Sundowner, That's exactly the kind of info i was looking for. Those numbers are pretty scary, particularly if i have to span roughly 30', but it's at least a ballpark number. Since you're a bridge engineer, what kind of specs do you think I am going to have to get it built to? I keep hearing HS20 thrown around. is that right? something else? Just want to be somewhat knowledgable before i start calling people.

I have a friend who is a civil engineer, but he doesn't do bridges. He was going to ask around, but i haven't heard from him recently.

Thanks!

 

[Sundowner]

without going too far into it, HS20 is a design loading that corresponds to an ideal heavy truck that weighs 36 Tons. On what is to me a very short span, this is typically a pretty easy load to carry. You will find that specs and minimum loads for bridges vary by state and county.

Now, you might get lucky in that many states have standard details for short span bridges and culverts, so there may be little if any design required. Your first stop should be to call the town engineer. He should have a structural engineer like me on staff or on retainer for situations just like this. If he doesn't, then call the County engineer's office and ask totalk to the county engineer or ***'t county engineer. they will either help you or direct you thier structural engineering consultant. Get the real deal from them.

your next stop should be the yellow pages for concrete precasters. Odds are pretty good that there is a precaster in your county that will sell you a pre-engineered precast culvert that your town will allow. they might even install it for you.

but do your homework first with the town/county engineers and see what they will allow.
be forewarned that town engineers tend to be a little, well.. "smalltowney" so make sure he understands fully what you're planning.

 

[carguy123]

I had the same issue and we just built a dam with an internal overflow and used the top for the road. Had do 2 of them so now I have 2 ponds and it helps the flood status downstream.

 

[Tommyo]

I did a little research on flat car bridges a while back, seems like an easy and inexpensive solution. They are already engineered to handle substantial loads and can be easily retrofitted with railings or different wheel tracks or decking and would only require the placement of two abutments. Also, someone mentioned using a box car and cutting the box portion of it off, this reduces the effectiveness of the structural design and reduces the load rating.
A google search of "flat car bridge" will generate some interesting companies that specialize in this as well as a few studies of these types of spans. I know that the timber industry uses them for their backcountry river/stream crossings and have no trouble driving loaded log trucks across. just my .02 cents seems like a neat project. best of luck

 

[Sundowner]

I found this website: http://www.railcarbridge.com/bridges.htm
very interesting idea, and they post thier prices on-line.
$40k for a 40x16 bridge is only $65-ish per square foot. not bad.

 

[Deltarat]

I did a little research on flat car bridges a while back, seems like an easy and inexpensive solution. They are already engineered to handle substantial loads and can be easily retrofitted with railings or different wheel tracks or decking and would only require the placement of two abutments. Also, someone mentioned using a box car and cutting the box portion of it off, this reduces the effectiveness of the structural design and reduces the load rating.
A google search of "flat car bridge" will generate some interesting companies that specialize in this as well as a few studies of these types of spans. I know that the timber industry uses them for their backcountry river/stream crossings and have no trouble driving loaded log trucks across. just my .02 cents seems like a neat project. best of luck

The flat bed would be less work involved. We picked ours up for just hauling it off. I don't think cutting the box off a car would reduce the strength enough to matter for a bridge to a home. They are rated for more than anything that can be hauled over the road anyway. We crossed ours every day with 75-80,000# loaded semi's. We would have used a flat car if we could have gotten one for the price we got the box. Just a suggestion of something that has worked for 45 years.

 

[spazzer]

http://www.tfhrc.gov/pubrds/fall95/p95a2.htm

Caltrans used some flatcars as a temporary bridge on I-5 back in 1995.

 

[Crusty Nut]

Lots of flatbed train cars used as bridges around here.

 

[Wardster]

Thanks Sundowner, That's exactly the kind of info i was looking for. Those numbers are pretty scary, particularly if i have to span roughly 30', but it's at least a ballpark number. Since you're a bridge engineer, what kind of specs do you think I am going to have to get it built to? I keep hearing HS20 thrown around. is that right? something else? Just want to be somewhat knowledgable before i start calling people.

I have a friend who is a civil engineer, but he doesn't do bridges. He was going to ask around, but i haven't heard from him recently.

Thanks!

Mike-

Sundowner is taking you down the correct path. I work for a bridge contractor and have helped a few home-owners get out of the jamb you find yourself in. We build the big bridges for DOT's, but I may be able to help you understand what you may be up against. Drop me an email through our website www.prestressedbridgesystems.com

-Wardster

 

[oldmanscj7]

I’ve saw one of these bridges: http://www.contech-cpi.com/bridges/11 installed in a residential application a few years ago. I’m not sure of the cost but it only took about 4 days to install.