Private roadway bridge over body of water.

[fastline12]

I will have to first mention that this is a private job on my own property but this is a bit outside my area of expertise and looking for standards and data to educate a bit for this as well as get opinions for experienced engineers in the field.

We are building a large pond with a dirt bridge crossing. Crossing will be approx 40-50ft long and 30ft wide. We will basically excavate the entire pond, then install flow pipes to communicate water flow from one side to the other, then back fill to create the crossing area.

I am not sure of what considerations to take regarding load ability of the crossing. I need to decide if PVC pipe is adequate under the crossing or if concrete will be needed.

Soil - sandy loam top, sandy clay under layer.
Max load - 150klb truck load. Not sure if need to break down to psi compression load.
Tube size - 2x, 30-40"
Tube set depth - 6ft
pond depth - 8ft


I realize this is a bit "vague" in data but looking for an overall opinion on the matter I guess.

 

[bridgebuster]

Yes your data is "vague"; it sounds like you want to build a series of pipe culverts. Take a look at this web site. You should be able to find what you're looking for.

http://www.conteches.com/Products/Bridges-and-Structures.aspx

 

[cvg]

PVC would not be my first choice for a culvert of this size. HDPE, RCP or CMP would be first choices.

 

[fastline12]

CMP would be an option but I have concern for long term life being submerged. RCP is my first choice but expense of that will kill this project just being a private project. I can work with a few different sizes but RCP is not typically found as surplus...

I mentioned PVC because we might have some removed C900 municipal water pipe laying around. They build highways over the stuff but this is a rather different application. I am just trying to arrive as compressive loads to determine if there is any suitability for PVC.

I may also be able to use smaller pipes. My target dimension is simply to reduce silt sealing concerns but I suppose some floable fill or something around the entrance could probably help.

 

[bridgebuster]

The Forestry Service has a mnanual for design of low water crossings; take a look:

http://www.fs.fed.us/eng/pubs/pdf/LowWaterCrossings/

 

[cvg]

what is your 150klb truck?

 

[fastline12]

Bridgebuilder, thanks for the link. I will take a look.

CVG, estimated truck load is just a worst case with margin. I am estimating an 80K lb freight load on an 18 wheeler. Crossing will see occasional truck traffic. We will have several concrete trucks crossing for a big concrete floor. probably 30 trucks at 80klbs each. Good test for the crossing I guess.

 

[Steeleguy]

This might work for your application.