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OPEN CUT SHORING DIAGRAM

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matt1829

Civil/Environmental
Feb 28, 2011
7
I got permission to Open cut the railroad and they said they wanted to see a shoring diagram due to liability purposes. Does anybody have any info on where I can take a look at any diagrams or what they might be looking for. Obviously, if we got permission to open cut, then why the hell would trains be going pass anyways?
 
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Open cut pipie installation will require additional work involving rail, ties, track leveling and other track material that generally must be performed by railroad employees at the expense of the person requesting the pipe crossing. Most of the railroads have outsourced this work, so you will be dealing with a railroad subcontractor.

Most of the railroads require expensive sheet piling when you are excavating within the railroad embankment.

In light of these issues, most people auger under a railroad.

You will have to obtain the services of a geotechnical engineer or structural engineer to prepare the shoring plan.
 
Generally, they will want to see stamped plans-they are looking to ensure that voids will not appear in future. You will need to state if shoring stays in place or gets pulled.
 
After construction and backfilling, all sheet piling within 10 feet (3.0m) of centerline track is usually cut off 18 inches (457 mm) below final grade and left in place.

Most of the railroads have detailed submittal requirements shown on their websites. Here is an example:

 
Of course if you are carrying out the work "open cut" there will be no trains. But that does not mean that their liability stops, men will be working down the excavation and they want to know that there is not going to be a tranech collapse.

The type of soil support or the profile of the batter will depend on the depth of the excavation and the type of soils. Why don't you just sketch what you propose and submit for review. Their approval might not absolve you of any responsibility, but as you are unsure it may give you some reassurance that everything has been taken into account before youstart work.
 
There are a great number of issues that can occur due to the trenching

There is the health and safety issue as mentioned
There is the failure of the embankment if the trench support collapses
There is the potential settlement of the railway if the trench support is inadequate (even if it has support)
Ther is the possibility for groundwater or rainwater runnof to cause pumping or corrosion or removal of fines or heaving related settlement.
If it is an embankment then the excavation could compromise the stability of the whole embankment.
Plus if it is on a sloping embankment there may be issues with the shoring method as there is much more soil on one side than the other.

Think yourself lucky, on this side of the pond they will not allow you to open cut within 6m of a railway without a fully checked and certified design, a method statement and a settlement survey plan and contingency plan(in case the items above fail to prevent a collapse) and you will also need a geotech report to back it up.

Track closure fines run in the hundreds of thousands per hour over here and I would expect that on your side they are probably similar. A shoring design is a small price to pay - cheap insurance as they say.

 
matt1829:

I am assuming you are excavating parallel to the tracks. The railroad will generally have a slope line, sometimes referred to as an influence line. It will slope away from the bottom of the tie at a 1:1 or 2:1 slope. Generally they require your excavation limit for the trench to be outside that line. Ask the railroad for their shoring requirements. It should be included in that. Draw a cross section to scale. Show your trench excavation and the railroad influence line. That is probably what they are looking for.
 
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