ouest-de-lîle Ouvrages d'art - Antenne Aéroport

[Enalung]

2 hours ago, Kolev3000 said:

C’est vrai… En même temps, il faut aussi qu’on dévéloppe l’expertise du tunnelier….Les 80km de tunnel de train à Montréal ont été construit avec l’ancienne technologie… Si on maîtrise le tunnelier ça va sûrement faire baisser les coûts des futurs prolongements et c’est peut-être un peu pour ça l’immobilisme des 30 ans dernières années…

According to her profile, she’s based at Genève so that’s why she wrote it at 3 am….Montreal hours…

Switzerland has been busy building several major tunnels in the last decade, including the record breaking Gotthard Base tunnel. Major portions of that tunnel were dug using more conventional techniques. The soil conditions were simply too extreme for a TBM. In one section, they had to freeze the ground, drill and blast, remove the muck as quickly as possible so that they could apply a layer of shotcrete, then a layer of reinforcements and another layer of shotcrete. By the time they stabilised the face of that portion of the tunnel, it had lost a full meter in diameter. One of their TBM got bogged down for months and had to be rescued with a pair of secondary shafts. The first one was a lateral shaft used to inject grout into the unstable fault. The second was dug in order to free the head and allow the TBM to progress forward. They make our definition of bad soil look like a bad joke.

My point is that TBM aren't necessarily the right answer to every tunnel. They are great in homogenous soil. If you listen to any documentary of tunnel building, there is very often a mention of following a specific geological layer. TBMs are built specifically for the soil conditions discovered during the surveys done along the route. If the route goes through several layers of rock, conventional techniques might be a better answer. Another solution might be to use several TMBs for different portions of the route. Montreal's geology is far from uniform.

[Enalung]

18 hours ago, Kolev3000 said:

Wow, what a wisdom and analyse/observation ... I'm happy to read you ☺️🥂

Most of what I know has been learned by watching documentaries and reading on the subject. I'm very curious by nature. Spend some time reading and you'll learn just as much given enough time.

[Decel]

Un marais se vide après le passage du tunnelier du REM

https://www.lapresse.ca/actualites/environnement/2021-08-12/un-marais-se-vide-apres-le-passage-du-tunnelier-du-rem.php

[SameGuy]

“Welp, there’s yer problem right there…”

[AMTFan1]

il y a 39 minutes, Decel a dit :

Un marais se vide après le passage du tunnelier du REM

https://www.lapresse.ca/actualites/environnement/2021-08-12/un-marais-se-vide-apres-le-passage-du-tunnelier-du-rem.php

Eh bien, il n'y a qu'une seule chose qu'on puisse dire: "Oups!"

[Decel]

Avec ça je ne serais pas surpris que ça renforce l'aversion de la CDPQi d'enfuir la portion sous R-L. Chat échaudé craint l'eau froide.

Notre expertise en TBM serait à peaufiner.

[crosbyshow]

il y a 20 minutes, Decel a dit :

Avec ça je ne serais pas surpris que ça renforce l'aversion de la CDPQi d'enfuir la portion sous R-L. Chat échaudé craint l'eau froide.

Notre expertise en TBM serait à peaufiner.

De toute façon..la Caisse enfouira jamais le Rem2..sous R-L...oubliez ça.

Le rem2 aura un tunnel de 8km dans l'est nord sud et le problème des tunnels est qu'on sait quand çela commence et combien ça coûte mais on ne sais pas quand ça finit et combien cela coûtera.

 

Tu regardes aller le Rem1 dans l'ouest en surélevé et ça clanche pas a peu près et il y a très peu de mauvaises surprises contrairement aux tunnels.

 

[SameGuy]

[SameGuy]

The whole reason they started the tunnel along Alfred-Nobel before Alexander-Fleming instead of at Chemin St-François as originally planned was in response to the BAPE’s multiple concerns about protecting the wetlands in Hubert-Reeves. 🤦🏻‍♂️🤷🏻‍♂️

[Monsieur_MA]

Il y a 3 heures, Decel a dit :

Un marais se vide après le passage du tunnelier du REM

https://www.lapresse.ca/actualites/environnement/2021-08-12/un-marais-se-vide-apres-le-passage-du-tunnelier-du-rem.php

C'est un double problème. L'eau qui manque dans le marais se retrouve dans le tunnel. Ce qui n'est pas souhaitable non plus.