Along a BNSF line in flat Nebraska yesterday, I noticed rows of what looked like 8" to 12" round creosote poles in line next to the tracks. They were spaced evenly about 3 to 4 feet apart, in a nice row parallel to the tracks, about 15 to 20 away. This was in flat farmland country, so they're not holding back a landslide or anything. The posts all poke up about 2' through the ballast at trackside. What did I see?
Thanks to Chris / CopCarSS for my avatar.
Murphy Siding Along a BNSF line in flat Nebraska yesterday, I noticed rows of what looked like 8" to 12" round creosote poles in line next to the tracks. They were spaced evenly about 3 to 4 feet apart, in a nice row parallel to the tracks, about 15 to 20 away. This was in flat farmland country, so they're not holding back a landslide or anything. The posts all poke up about 2' through the ballast at trackside. What did I see?
I have seen those along the Sioux City Sub (Sioux City IA to Ashland NE via Fremont), which I assume is the line you're talking about?
If so - then they are in indeed timber piles installed to stop the embankment from sliding in what the geotech people call a "global stability failure". The land is flat, but the subgrade is terrible.
Dan
MC, your thoughts please.
dpeltier Murphy Siding Along a BNSF line in flat Nebraska yesterday, I noticed rows of what looked like 8" to 12" round creosote poles in line next to the tracks. They were spaced evenly about 3 to 4 feet apart, in a nice row parallel to the tracks, about 15 to 20 away. This was in flat farmland country, so they're not holding back a landslide or anything. The posts all poke up about 2' through the ballast at trackside. What did I see? I have seen those along the Sioux City Sub (Sioux City IA to Ashland NE via Fremont), which I assume is the line you're talking about? If so - then they are in indeed timber piles installed to stop the embankment from sliding in what the geotech people call a "global stability failure". The land is flat, but the subgrade is terrible. Dan
Czechs ?
Shell piling -usually a long discredited practice used to hold up shoulders an embankments that are too steep and gap-graded with the material having too many fines and/or organics in it leading to slope failures. Possibly also has a lagging (dump plank) wall hidden just out of site. Hell on Jordan Spreaders, Shoulder Cleaners, Undercutters and ballast regulators. Since the advent of lime injection, geogrid and advanced soil mechanics, you don't see much of it anymore.
If you've ever watched the old Wabash west of St. Louis along I-70, you will see plenty of it along with locations out in the swamps. (especially in areas where you don't have the real-estate to flatten out [lessen] the side slopes)
Big indicator of your local soils historically being not worth crap. (and there is not much better soils for many miles in any direction to replace fills with.)
Murphy Siding You're right on! Sioux City to Fremont trip. The subgrade is terrible? Is that related to the entire state of Nebraska sitting on top of a sand pit?
You're right on! Sioux City to Fremont trip. The subgrade is terrible? Is that related to the entire state of Nebraska sitting on top of a sand pit?
No, I don't think so. If it's anything like South Sioux, it's a thick layer of fat clay right under the topsoil that loses most of it's strength when wet. I spent a very bad week dealing with that crap a few years ago. Being 2,000' from a slaughterhouse didn't make it better.
Somewhere I might still have a geotech report prepared in preparation for some new siding / siding extension projects on the line. I don't remember the details, whether it was exactly the same stuff as South Sioux, but I remember a lot of discussion about how to deal with the subgrade. In the end, like most such projects, they got canceled before engineering was completed.
mudchicken Czechs ? Shell piling -usually a long discredited practice used to hold up shoulders an embankments that are too steep and gap-graded with the material having too many fines and/or organics in it leading to slope failures. Possibly also has a lagging (dump plank) wall hidden just out of site. Hell on Jordan Spreaders, Shoulder Cleaners, Undercutters and ballast regulators. Since the advent of lime injection, geogrid and advanced soil mechanics, you don't see much of it anymore. If you've ever watched the old Wabash west of St. Louis along I-70, you will see plenty of it along with locations out in the swamps. (especially in areas where you don't have the real-estate to flatten out [lessen] the side slopes) Big indicator of your local soils historically being not worth crap. (and there is not much better soils for many miles in any direction to replace fills with.)
dpeltier Murphy Siding You're right on! Sioux City to Fremont trip. The subgrade is terrible? Is that related to the entire state of Nebraska sitting on top of a sand pit? No, I don't think so. If it's anything like South Sioux, it's a thick layer of fat clay right under the topsoil that loses most of it's strength when wet. I spent a very bad week dealing with that crap a few years ago. Being 2,000' from a slaughterhouse didn't make it better. Somewhere I might still have a geotech report prepared in preparation for some new siding / siding extension projects on the line. I don't remember the details, whether it was exactly the same stuff as South Sioux, but I remember a lot of discussion about how to deal with the subgrade. In the end, like most such projects, they got canceled before engineering was completed. Dan
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