Toronto GO Transit: Davenport Diamond Grade Separation | ?m | ?s | Metrolinx
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Allandale25
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EnviroTO
Senior Member
I can't say I look at those thin walls filled with dirt and think "this is going to last 100 years". Hopefully under this dirt they are running weather resistant tensioning wires between the two walls to hold them together a fixed width.
Those vertical pipes are an interesting new addition. Maybe Metrolinx news will explain
Those vertical pipes are an interesting new addition. Maybe Metrolinx news will explain
beatle04
New Member
I can't say I look at those thin walls filled with dirt and think "this is going to last 100 years". Hopefully under this dirt they are running weather resistant tensioning wires between the two walls to hold them together a fixed width.
Those vertical pipes are an interesting new addition. Maybe Metrolinx news will explain
Pretty sure the wall design is the exact same use in modern day road overpasses (or at least I've seen that wall pattern on overpasses around the city).
sche
Active Member
They’re MSE (Mechanically Stabilized Earth). The thin walls are not actually structural, it’s the dirt/sand holding the weight. Reinforcement embedded in the dirt holds the dirt together. It’s the same stuff used on highway ramps, some retaining walls, and the like. It’s actually a pretty interesting technology.
Mechanically stabilized earth - Wikipedia
ShonTron
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They’re MSE (Mechanically Stabilized Earth). The thin walls are not actually structural, it’s the dirt/sand holding the weight. Reinforcement embedded in the dirt holds the dirt together. It’s the same stuff used on highway ramps, some retaining walls, and the like. It’s actually a pretty interesting technology.
Mechanically stabilized earth - Wikipedia
en.m.wikipedia.org
This is how many railway embankments were created. Often, the railway would cross a valley or gorge on a simple wooden trestle. Trains would have to go slow and light, but it’d get revenue started quick. Over time, earth would get dumped between the wooden lattice, eventually making it as strong as level ground, allowing higher speeds and heavier loads and locomotives.
This appears to be the modern technique for a time tested principle.
nfitz
Superstar
There's historical photos showing that this is how the embankment for the CN mainline from about Pape to Union Station was constructed back in the 1920s (and 1930s?). You can also see photos of this being how streetcar tracks and roads were built across some of the ravines that were filled in - such as Upper Gerrard Street.
EnviroTO
Senior Member
Ok, so there is a horizontal tensioning element (i.e. soil reinforcements) both holding the soil together horizontally and holding the wall against that soil. I guess in the pictures any of those soil reinforcements have already been covered with compacted dirt.
vic
Senior Member
Concrete Railway Ties by Vic Gedris, on Flickr
These have been stacked up in the Wiltshire Ave. hydro corridor for a while.
Allandale25
Senior Member
max
Active Member
If it means the same as it does in Australia then it would be Traffic Classification. T6 are rated for a maximum tangent speed of 80 km/h.
Source: https://www.transport.nsw.gov.au/system/files/media/asa_standards/2019/spc-232.pdf
smallspy
Senior Member
That's absolutely not the case here. The type of tie has no bearing on the speed limit of the track.
It could be a project classification (T6 maybe denoting the south Barrie Line improvements?), or a location marking for within the project they are to be used. But there is nothing regulatory about the term "T6".
Dan
