geotechnical investigation for a railroad

[Silty]

Hi Everyone,
I am currently involved with geotechnical investigation for a railroad embankment. Can you advise what should be the distance between holes and depth of investigation? What parameters are important and should be considered.
The embankment is 11 m wide and 1.5 high and there are two rail road sidings(low speed to let the train stop)
I think settlement/heave is critical for this case, since the tolerances for the railway is limited.
Any comment on ballast for the embankment will be great,
Thanks

 

[oldestguy]

Get any info you can get on the geology as well as the pedologic mapping which will help. That way you can get a better idea on where the better or worst places may be. If the budget will take it widely spaced borings is usually the rule, with the option to add more where some question may come up. As to ballast, most railroads have their own system. My experience with railroads has been that they are set in their ways and building anything new is governed by those ways. Newer engineers there have never built anything so you will be talking to beginners as to construction.

 

[Silty]

Thanks oldest guy, the project is located in Southern Ontario, Canada and based on available information I expect to get clayey silt there. My original proposal was 4 boreholes spaced every 50 m but then I added 2 boreholes, just in between if there is any change in soil condition. As you said, I should see what are the regs for the railroad and follow that.I will have the ballast more than frost depth to avoid heave, but still confused about the settlement criteria.
I agree, these railroads are all built decades ago and we are all considered new engineers to those projects.
Regards,

 

[EireChch]

How long is the portion of embankment you are looking at?

 

[Ron]

Try the American Railway Engineering and Maintenance Assoc (AREMA). They have a lot of publications for design and enginerring.

 

[fattdad]

Another vote for AREMA. It's all spelled out.

f-d

ípapß gordo ainÆt no madre flaca!

 

[Silty]

Thanks for the reference,I will look at it.
Its almost 200 m and its two lines as siding , so I expect that it won't have high speed.