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NBCC 2020 Climatic Data 2

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EngDM

Structural
Aug 10, 2021
389
I have sometimes had to contact environment Canada to provide Ss and Sr values for projects since they provide very little tabulated values in Manitoba. I'm wondering if anyone has a bunch of these laying around from past jobs that we could create a larger database than what the NBCC Table C-2 provides.

Currently, I have data for the following places:

Manitoba:
[ul]
[li]Lundar[/li]
[li]Arbakka[/li]
[li]Ebb and Flow[/li]
[li]Okno[/li]
[li]Russell[/li]
[/ul]

Northwest Territories:
[ul]
[li]Lutselk'e[/li]
[/ul]
 
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STpipe said:
Wouldn't that information just be pulled from the NBCC seismic hazard map online?

I'm looking for the snow and wind load values. The seismic hazard map does not provide these.
 
Ah, sorry, I just saw you were looking 'S' values without looking too closely at the subscript and assumed you were looking for seismic values.

For non-seismic parameters, I don't think there is a tool available similar to the seismic hazard tool, or something like the ASCE 7's hazard tool unfortunately. The closest is jabacus, but for non-seismic parameters it's just a database of the tables contained in the NBCC tables.
 
STpipe said:
For non-seismic parameters, I don't think there is a tool available similar to the seismic hazard tool, or something like the ASCE 7's hazard tool unfortunately. The closest is jabacus, but for non-seismic parameters it's just a database of the tables contained in the NBCC tables.

Yea exactly this. Environment Canada can give you the values if you contact them, but there is a fee per request. We have obtained the values for places in the OP, but I'm inquiring to see if anyone else has done this for other locations.
 
Yeah, that's unfortunate. It's so bizarre because most other design codes provide environmental parameters as contours, based on zones as opposed to very specific locations.

The only other suggestion would be to look at some of the old editions of the NBCC (like 50s and 60s). I believe those contained contour maps. You would need to do a comparison between the values in the old code and the current code as known locations to see if there has been any significant changes.
 
Just call Env Can.

It's 200 bucks and you have something to hang your hat on. A little difference in elevation can make a huge difference in snow load, to name just one example.

 
atrizzy said:
Just call Env Can. It's 200 bucks and you have something to hang your hat on. A little difference in elevation can make a huge difference in snow load, to name just one example.

See below:

EngDM said:
Yea exactly this. Environment Canada can give you the values if you contact them, but there is a fee per request. We have obtained the values for places in the OP, but I'm inquiring to see if anyone else has done this for other locations.

I'm not sure why they don't just create a tool similar to the seismic tool for this.

 
EngDM, my comment was more to point out that the fee is small with respect to what it could mean for your designs, especially if you're dealing with a remote site.

I do remote site designs all the time and have them on speed dial.

I suspect there's more to it than the seismic calculator. I think they look at topography, elevation, a bunch of factors that may not be easily programmable. Or maybe I'm wrong and it's in the works, who knows.
 
Its manitoba so I would just pick a conservative value nearest to you. Unless it super far it is fine.

I would say this is reasonable because if they deemed your area was a niche 'climate' they should have added it in. Or else it is assumed to just be blended into the rest of the contours.
 
WestLevel said:
Its manitoba so I would just pick a conservative value nearest to you. Unless it super far it is fine.

We did this once, took the highest value present for the 4 nearest NBCC tabulated values in a circle around the site. Contacted environment Canada just to be sure near the end and the snow load was higher than anything in the surrounding area.

 
They don't have a tool like for seismic because a bunch of the snow and wind stuff has some hand massaging that's been happening to it, so it's not really a consistent geographic gradient. They have a mapped dataset like they do for seismic but it hasn't been released in the same way. There are lots of areas with minimal datasets, different recording periods and all sorts of fun statistical effects.

I played with wind and seismic maps using some python libraries a few years ago. I took all the locations that I had from the provincial codes and then did some nearest neighbor averaging to create a regular grid and then did contour maps. It doesn't really work.

This paper has a better treatment of wind maps than I managed to do:


There are some articles with similar things for snow loads out there as well.

This is useful for study level stuff at least.
 
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