Francis:
I agree.... to disagree. You guys and your darn new editions of codes, you’re outpacing me at warp speed. I don’t even get started digesting one, when I’m getting another one rammed down my throat. Tell your legislators not to adopt the next one and explain that they won’t have building falling down around them while doing this, you want to learn to understand the one you have now. And then, each time the question becomes... but there is still some unusual, unlikely, unanticipated condition that isn’t explicitly addressed by the new edition, now what do we do. People loads do cause vertical loads and lateral loads and we better design for all reasonably anticipated lateral loads. What the heck ever happened to a little common sense and engineering judgement and experience? The code just sets the min. magnitude of the loads it lists, it certainly doesn’t say you don’t have to consider other possible or likely loads, and I don’t see any “what if’s” about that. You are sorta asking that a code be written to take this experience factor into account in such a way, that any damn fool (and, I don’t mean you) can do the almost impossible without any thought or knowledge about what he/she is doing, or the consequences thereof. As a structural engineer, I always thought that the only loads I had to design for were those which might make my structure fail, become unserviceable, seriously harm someone or not perform the function for which it was intended and being designed. All the other loads and conditions would take care of themselves. I never thought to scour the code to see if meteorite impacts, or tsunami waves on a high desert plateau, might affect my structure; the old common sense, judgement, experience thing again, or in accordance with well established engineering principles and practice.
To me, ‘where applicable or as applicable’ means if it is reasonably likely to occur, design for it. That’s what your 2nd and 3rd paras. say. While SIMPSON’S guide is a good guide for alerting you to all the potential problem details, remember they are trying to sell their hardware, it may not all be req’d. Reread my 22DEC10 post, I give a few fairly simple examples of what to watch for or when to call for help. Send me copies of those code sections and that SIMPSON guide so I can take a look at them. Maybe we can discuss some other details or items to watch for.
It should be sufficient to say that the deck should be supported in such a fashion as to take all of the anticipated loadings imposed upon it, in the process of performing its intended function. And, IF YOU do not know that means, you have no business building that deck, and you should hire someone who really does know what he/she is doing, if you want a permit. Furthermore, this code section does not protect every damn fool from his/her ill thought out actions.
There are several pretty good deck design guides out there and I think I would just hand out copies of one of them along with the applicable code sections. I’m not sure I would want to try rewriting the history of Structural Engineering, on my own, for public distribution. That’s just sticking your neck out a mile, even if it is tough to sue you guys, for little gain in the public’s ability to grasp the nature of the problem. Do this study for your own edification, to develop your own check list of what to watch for, so when you check a deck plan (I don’t like the words approve or bless in this context), you know when to tell them they need an engineer to do this if they want a permit. You don’t need to give them your check list, but if they miss too many items on it, that might be an indication that they have no idea what they are doing and need some design and building help, and closer inspection.
The question then becomes: should we design for 10 dancing cheerleaders or 5 defensive linemen and that’s further complicated by the fact sometimes there are only three down linemen and at others they are all dancing even the linebackers. Where do you draw the line, the code doesn’t cover this, common sense and judgement does. So, now lets argue about the meaning of reasonably likely.
We can’t design against or codify things to prevent stupidity or to compensate for lack of knowledge. Some of them just exist. And, hopefully natural selection weeds them out, without the courts blaming their existence or actions on you and me.