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Large culverts and railway crossings

Large culverts and railway crossings

Large culverts and railway crossings

We have several 3M x 3M culverts to install which will carry raw sewage.
Part of the route means that there are railways to cross.

I am familiar with pipelines but have no experience with pre cast concrete culverts.

What are some of the basic installation requirements for installing in normal rights of way in terms of cover above top of culvert, recommended depths under railways/ roads.

Is the culvert required to be leak tested? Can the culverts be isolated in a similar way to pipelines for inspection purposes?

If there are some companies that produce standard details I would be grateful for any recommendations.

It would also be useful to see what construction methods are possible which minimise construction time. I have seen the railway section removed whilst a culvert has been installed on one YouTube video but it was 4 smaller culverts for drainage reasons. I didn't know the exact size of the culverts on the video but they were about 3/4 of the installers height. So not as large as the single culvert we are installing.

Best Regards

RE: Large culverts and railway crossings

American Concrete Pipe Association - ACPA "concrete pipe & box culvert : Installation manual 2012


Furthermore You can use the software (free download) called CANDE Culvert ANalysis and DEsign
(Google simply CANDE)

RE: Large culverts and railway crossings

Many thanks robyengIT

RE: Large culverts and railway crossings

If carrying raw sewage, then you have to have good soils, else, the joints between precast units may leak. Maybe special seals.

Roby... thanks for the info.


RE: Large culverts and railway crossings

In the USA the railroads have some pretty strict rules when operating on their property. You probably have to run your plans by them for approval before you start and it may be like dealing with another country.

RE: Large culverts and railway crossings

What would be a typical joint specification for raw sewage culverts? And I heard that the H2S is medium to high levels....
But not saline.


RE: Large culverts and railway crossings

Are these culverts or cast in place concrete channels? Long cast in place channels carrying raw sewage would be very unusual. They would be more typical in sewage treatment plants, As others have suggested above, this is usually done with pipes.
JohnWeal, this is a complicated design. You need to find someone who's done it before. The portion under the railway is the least of your worries. The railways have tables with values of surcharges for under-railway designs. There's linings, waterstops and access to consider.

RE: Large culverts and railway crossings

JedClampett, the construction and civil design will be done by others.
But as we are writing specifications etc for the project, I would like an overview of the engineering involved and what International specifications need to be complied with as a minimum.

So is it not normally done in culverts 3m x 3m with such large flows? Sure I have only been involved with pipelines too but I have the site pastures that show all culverts which we have to butt up to.

RE: Large culverts and railway crossings

John, for a 3m x 3m culvert, I would expect a 10'-0" diameter pipe would do the job. I'm not saying a culvert is out of the question, but pipes come with their own sealing, coating and installation procedures. For a culvert, you would have to pour a slab, with waterstops, then pour walls, then a top slab. There's a lot of labor. And for the top slab, there's shoring. For pipes, you get a 20'-0" long piece of pipe, push it on the piece that was installed before and you're done. All the tedious labor is done in the pipe suppliers yard. You can get pipe with PVC liners already installed. You can bore and jack pipes under the railroad (it will be a large bore and jack). The railroads are used to this. I'm not sure how you would install a cast in place culvert under a railroad, without open cutting it.
Culverts would be an "unusual" choice. I'm not sure of your flows, but I suspect there's a pipe that would work.

RE: Large culverts and railway crossings

If you are talking about railroads in the US, then you need to plan a bore and jack. I think you're wasting time considering an open cut, particularly if you haven't discussed with the railroad yet.

RE: Large culverts and railway crossings

Many thanks for you comments....
Will keep you updated once I receive more information on flows etc.
The project is in Northern Iraq.

RE: Large culverts and railway crossings

As oldestguy said RR people will be tough on safety as I know from experience when the construction firm that I worked for added an additional lane on I95 NB over Amtrack lines in Bridgeport, Ct. back in the 1990's.

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