Angle for elevated track fill?

[harrym]

I am building a logging branch that climbs to a plateau about 65 feet above the main line.  This will involve building a fill that is about 40 feet high across an open area.  The roadbed at the top is 1.5" wide.  How wide should the fill be at the bottom [3" lower]?  Is there a standard angle of fill that was used?

[up1950s]

The angle of repose ( the angle that which a aggregate comes to rest ) , depends on the aggregate , but 45 degrees would be pretty stable though a bit too wide , 55 degrees would look natural IMO . Many fills were on top of trestles that were there first .

http://en.wikipedia.org/wiki/Angle_of_repose

http://history.gsmrrclub.org/history5e.html




More info here

http://books.google.com/books?id=ygKio-Ks0doC&pg=PA296&lpg=PA296&dq=track+fill+angle+of+repose&source=bl&ots=AG65lEwkyl&sig=eb6tZIPQ80_X2cBBlUus4HvRggU&hl=en&ei=lOW9SYydL9mLtgfwiM34Cw&sa=X&oi=book_result&resnum=7&ct=result

[randgust]

A logging railroad will live with the angle of repose of the material, maybe...maybe...1:1 (45-degrees).  Current engineering standards are almost univerally 2:1 (30 degrees).

[Walkercolt]

Dirt will spread-out more due to erosion effects too. In Okie red-clay close to 1.5:1, more in loam soils, and that's about everything I remember from "Statics and Strengths" class about soils and gravels. Oh yeah, better drainage in soils steepen their angle of repose some. Man, it's been a LOOOONG time since that class, and I've never used anything I learned, and I sold my textbook. I'd forgotten how much I've forgotten. :-[