Deck lateral load 4

[DoubleStud]

So, what do you typically do now when you design a deck? How much lateral load do you use? Do you calculate the tension chord force at the end of the deck and use a tension hold down device like IRC Figure R507.2? According to NDS, the allowable shear capacity of a deck with horizontal decking member is only 70 plf. I have a deck with really tall columns (20 ft). The columns and beam will not give that much restraint laterally. I read an article somewhere about a test on the deck where people move left and right simultaneously and it generated about 12 psf of deck area laterally in the middle. That seems crazy high. Luckily the deck has a pretty good width to depth ratio (24 X 11). I just want to make sure I do this correctly since the columns are so tall. Any advice?

 

[XR250]

@DoubleStud

Something like this......

 

[bones206]

As always, the designer should be aware of potential unusual loading patterns in the structure that are not covered by these minimum standards.

ASCE definitely needs to add some figures in the commentary illustrating some examples of these "unusual loading patterns".

 

[zackngineer]

@bones206: Cmon, I would think that engineers can draw on their deep knowledge and experience with frat parties to envision these loading patterns!

 

[Tomfh]

and decks 40 psf.

Same in Australia. 2kPa for residential balconies and decks. And only 1.5kPa if less than 1m above ground. These numbers have always seemed way too low for me.

Here's 2kPa (40psf). It's far from packed.

Loads of this magnitude (or higher) are fairly common in private residences, and break many a deck:

 

[bones206]

That 2nd photo would be perfect for the asce commentary.

 

[lexpatrie]

I propose we all gather on a deck 2 feet off the ground and "simulate" a party with a fully instrumented "test deck".

Or can we build a second story addition on my house so we have a deck to attach to that's off the ground and then put some crash cushions under it for the "experimental study"? We can invite Frank and Don to set up the instrumentation.

I'm centrally located, so....

On a more serious note, the pattern loads are specifically addressed when there's a cantilever, i.e. along the rail.

That photo.. yikes.