Snow load on grating
Snow load on grating
(OP)
Does anyone have any references or opinions for how to account for snow load on grating?
For the most part, snow passes relatively easily through any large grating, however I usually include snow load in my calculations knowing it won't govern because the National Building Code of Canada includes a clause that says that pedestrian only areas do not need to apply occupancy and snow at the same time.
However, in this case, I'm involved in a project with very controlled access with a small occupancy load in a situation where it will be quite expensive to build in extra capacity for unrealistic snow loads. Parts of the structure are to be in the water and will be supported via buoyancy and the snow load would be incredibly significant. Technically, the NBCC (or, rather, the provincial building code derived from it) won't apply to this structure, but I'm following the general thrust of it anyway. Snow load only needs to be accounted for on surfaces that snow can accumulate on and while snow can't really accumulate on grating significantly, there is generally still a little bit that sticks around that should be accounted for, even in the best case.
I'm also slightly concerned that with icing the holes of the grating could provide surface area for snow buildup, but it hasn't been observed in a similar installation.
I'm actually surprised that I haven't been able to find a grating manufacturer that's done a relatively quick study they can use as a selling point.
What have other people done with regards to grating and snow? I'm fairly sure that a significant amount of snow can't accumulate, I'm just arguing with myself over whether I can properly justify that opinion if I ever need to back it up.
For the most part, snow passes relatively easily through any large grating, however I usually include snow load in my calculations knowing it won't govern because the National Building Code of Canada includes a clause that says that pedestrian only areas do not need to apply occupancy and snow at the same time.
However, in this case, I'm involved in a project with very controlled access with a small occupancy load in a situation where it will be quite expensive to build in extra capacity for unrealistic snow loads. Parts of the structure are to be in the water and will be supported via buoyancy and the snow load would be incredibly significant. Technically, the NBCC (or, rather, the provincial building code derived from it) won't apply to this structure, but I'm following the general thrust of it anyway. Snow load only needs to be accounted for on surfaces that snow can accumulate on and while snow can't really accumulate on grating significantly, there is generally still a little bit that sticks around that should be accounted for, even in the best case.
I'm also slightly concerned that with icing the holes of the grating could provide surface area for snow buildup, but it hasn't been observed in a similar installation.
I'm actually surprised that I haven't been able to find a grating manufacturer that's done a relatively quick study they can use as a selling point.
What have other people done with regards to grating and snow? I'm fairly sure that a significant amount of snow can't accumulate, I'm just arguing with myself over whether I can properly justify that opinion if I ever need to back it up.






RE: Snow load on grating
for outdoor signs in New York city we ignored the snow load though I do concede that you have a valid point about icing.
To allow for this look up what the angle of recline is for the snow mound from the edge and this will give you a much greatly reduced snow than the full normal load.
Hope this helps.
RE: Snow load on grating
Dik
RE: Snow load on grating
The only exception that I can remember was during a re-fit. A lot of pipe was laid out on boards on the floor, enough to provide a base for the snow. However, that was a special condition, not a requirement of the original design, we checked on it as part of the refit design.
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Snow load on grating
I had actually considered working out a load reduction based on that concept. Unfortunately, when I started working through it I realized that I've seen fresh snow pile up with perfectly vertical edges for well over a foot of height on my very own patio table. Snow has a fair amount of cohesion and, while I'm sure it will rearrange itself to a stable angle if it grows high enough or is disturbed (avalanche anyone?) I'm not sure if it's really a valid assumption for reduction of loads?
dik, this is something I'm concerned about. I know that if we somehow transported a two foot covering of snow onto the grating it would manage to bridge the gaps. I just can't really work out a way that it would get to that stage on its own. The bars are so thin in comparison to the grating holes. How can enough snow gather to bridge the holes before it loses stability and falls through the grating?
RE: Snow load on grating
Designing for full snow load would be my approach if the openings are less than about 2" in either direction. Could consider a reduction for larger openings.
BA
RE: Snow load on grating
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Snow load on grating
Dik
RE: Snow load on grating
BA
RE: Snow load on grating
I would not combine it with other Live Loads. If this is something that needs to get used during the winter, then they would probably shovel the snow away for access.
RE: Snow load on grating
RE: Snow load on grating
Dik
RE: Snow load on grating
1. Full Live
2. Full snow
3. Full live and .5 snow
4. Full snow and .5 live
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Snow load on grating
BA
RE: Snow load on grating
Dik
RE: Snow load on grating
Is the water muddy enough yet?
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Snow load on grating
RE: Snow load on grating