montréal REM de l'Est

[mickael]

Le principe de tranchée couverte, utilisé pour une partie de la deuxième ligne du métro de Rennes a t'il été étudié ? Notamment pour la partie situé sur la rue Notre Dame Est....?

Voici un lien expliquant le principe : http://www.metro-rennes-metropole.fr/accueil/les_travaux/methodes_de_construction/tranchee_couverte

 

[p_xavier]

12 minutes ago, mickael said:

Le principe de tranchée couverte, utilisé pour une partie de la deuxième ligne du métro de Rennes a t'il été étudié ? Notamment pour la partie situé sur la rue Notre Dame Est....?

Voici un lien expliquant le principe : http://www.metro-rennes-metropole.fr/accueil/les_travaux/methodes_de_construction/tranchee_couverte

 

Ce principe est utilisé (moins profond par contre) pour le O-Train dans le prolongement à l'ouest de la ligne 1 à Ottawa. La CCN ne voulait pas de train car ça gâchait le paysage de la rivière, pour les automobilistes sur l'autoroute...  Une bonne section de la Canada Line sous Cambie à Vancouver était également en tranchée couverte.

[Enalung]

1 hour ago, p_xavier said:

Ce principe est utilisé (moins profond par contre) pour le O-Train dans le prolongement à l'ouest de la ligne 1 à Ottawa. La CCN ne voulait pas de train car ça gâchait le paysage de la rivière, pour les automobilistes sur l'autoroute...  Une bonne section de la Canada Line sous Cambie à Vancouver était également en tranchée couverte.

Le problème, c'est qu'il y a l'intercepteur sud qui longe Nôtre-Dame sur une bonne distance. J'ignore à quelle profondeur il est situé, mais il faut en tenir compte.

[SameGuy]

1 hour ago, Enalung said:

Le problème, c'est qu'il y a l'intercepteur sud qui longe Nôtre-Dame sur une bonne distance. J'ignore à quelle profondeur il est situé, mais il faut en tenir compte.

…Among other problems with the idea.

There’s just no logical reason to bury a suburban train line that goes through such an empty area overall — it’s about as dense as the West Island. There’s a reason why most metros and S-bahnen around the world are surface-running outside of the CBD.

[andre md]

Il y a 10 heures, SameGuy a dit :

Then why not build at ground level? Surely a few viaducts or road over/underpasses are cheaper and easier to design and build than an entire elevated line (talus or aerial guideway, peu importe). 

A train going by at 50-70-90 km/h every two minutes in each direction doesn’t make for a pleasant bike path or “High Line.”

Rem A , Donney spur could have been build at ground  level,  not so many streets  are crossing this section and it pass behind the building. 

 

[SameGuy]

42 minutes ago, andre md said:

Rem A , Donney spur could have been build at ground  level,  not so many streets  are crossing this section and it pass behind the building. 

 

Indeed. I think about a thousand pages ago in the REM-A thread we discussed that (briefly). At least they kept most of the 28 km of DM line from Portal Heights to St-Eustache at ground level, building viaducts where necessary along with the one elevated segment in Pierrefonds.

[geraldshaw]

New York Times today - front page investigation of Mexico City elevated metro line collapse 

https://www.nytimes.com/interactive/2021/06/12/world/americas/mexico-city-train-crash.html

[SameGuy]

Which has ZERO to do with this topic.

[geraldshaw]

3 hours ago, geraldshaw said:

New York Times today - front page investigation of Mexico City elevated metro line collapse 

https://www.nytimes.com/interactive/2021/06/12/world/americas/mexico-city-train-crash.html

 

2 hours ago, SameGuy said:

Which has ZERO to do with this topic.

If so,  then surely  you will agree that  the  drawings by the Caisse Infra just above of "trace ariens dans le terre-plein central" on Rene-Levesque also have "ZERO" to do with this topic. Go figure. 

2 minutes ago, geraldshaw said:

 

If so,  then surely  you will agree that  the  drawings by the Caisse Infra just above of "trace ariens dans le terre-plein central" on Rene-Levesque, Notre Dame and Sherbrooke  also have "ZERO" to do with this topic. Go figure. 

 

[Enalung]

40 minutes ago, geraldshaw said:

If so,  then surely  you will agree that  the  drawings by the Caisse Infra just above of "trace ariens dans le terre-plein central" on Rene-Levesque also have "ZERO" to do with this topic. Go figure. 

We had a discussion about this when it initially happened. Most of us concluded that it was shoddy work. The article you linked bares this out quite clearly. I read it in full. I completely agree with SameGuy. This is not relevant the REM discussion. We have stringent laws and safety checks in place to ensure that something like this does not happen. Approvals are required at every step. Everything is closely logged for future references. Many structures, such as the Samuel de Champlain bridge, are covered in sensors that can detect even the slightest movement. Some movement is expected and tolerances are typically built in to allow for that mouvement, but anything beyond tolerances is grounds for an investigation.

The Mexico viaduct was reported to be "dancing" even before it was officially opened. Had that structure been built in Québec, I have every reason to beleive that the government would never have approved delivery and might even have required the structure to be torn down and rebuilt from scratch. We've been quite proactive theses last few years at tearing down structures that are not up to modern standards and might potentially be dangerous.

You don't want a viaduct on René-Lévesque, and neither do many of us, but this isn't the way to go about it. This kind of fear mongering makes it very easy to dismiss and discredit the opposition.

This is also why I call bullshit on CDPQ saying that "buildings might collapse". In London, when they dug the latest tunnels under historic buildings, they rigged every single building along the way with an array of sensors. Mouvements could be detected in real time. All of the work would be shut down long before any abnormal mouvement actually threatened to collapse a building. We're not that careless. I have every reason to beleive that we would implement similar measures.