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ASCE 7-10
3

ASCE 7-10

ASCE 7-10

(OP)
Got the new 2010 in the mail today.  That sucker doubled in size from the '05 version.

What's happening here people?

There's a 1961 version of ACI 318 on my company bookshelf that's only 30 pages.

RE: ASCE 7-10

What are you complaining about - you got 10 for the price of 5.

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: ASCE 7-10

Let me guess--the wind and seismic sections doubled in size.

When I started my career, the wind load section of the Wisconsin Code was one paragraph:  you designed MWFRS for 20 psf for buildings under 50', with the wind load increasing for taller buildings.

How is it that all of those "incorrectly" designed buildings are doing just fine?   

DaveAtkins

RE: ASCE 7-10

I always wondered the same thing with wind loads.
It is getting ridiculous.
I think the Empire State Building was one of the first tall buildings to even incorporate wind loads and even then I think it was just some nominal lateral load.

I just started really getting familiar with what little changed in 2005!!!!!!! :(

RE: ASCE 7-10

(OP)
If I wanted 1000 page books on my shelf, I would have become a lawyer.

RE: ASCE 7-10

The good news is that with the code cycle the way it is, no one will adopt ASCE 7-10 for about five years.  So we'll all be five years closer to retirement (or death).

RE: ASCE 7-10

(OP)
from looking at it for about 5 minutes, I can tell this

1. seismic map for S1 stayed the same
2. seismic map for Ss decreased acceleration values on average of 0.05 for each curve
3. they turned one chapter of wind into 6 chapters. I seriously wonder who will use ASCE's 6 wind chapters when IBC just simplified theirs.

RE: ASCE 7-10

It looks like ASCE is following New Zeland and Austalia on the wind.  Corner, edge, and endzones are nothing to them.  They have about 10 different zones on the roof surface for variable wind load.

RE: ASCE 7-10

Is there a list of all changes between '10 & '05?
IV

RE: ASCE 7-10

Are the sets construction dovcuments that you all are creating getting larger as well?  Seems like i have 2 to 3 times as many sheets of compared to 10 years ago!

I blame computers :)

RE: ASCE 7-10

Florida is trying to fit in the ASCE 7-10 into the next code cycle, so it would be effective sooner than usual.

RE: ASCE 7-10

I know that they have changed the 3-second gust wind speeds from service length to strength level.  Not sure exactly how this works out with the return intervals, but the LRFD load combinations have been changed with the 1.6W term being replaced by 1.0W.

RE: ASCE 7-10

Quote:

How is it that all of those "incorrectly" designed buildings are doing just fine?

We have these things called factors of safety which help out a lot.

But the point is well taken here. Any building that is still standing is clearly safe and reliable.

RE: ASCE 7-10


Quote:
"Any building that is still standing is clearly safe and reliable."

Could I interpret this statement as: "Any collapsed poor design building is safe and reliable before the moment it collapsed"?

RE: ASCE 7-10

(OP)
well, they've now got 4 different wind maps for the 4 different risk categories which has replaced importance factors.

my firm just printed some shirts that say "if you see us running from your building, you'd better keep up."

RE: ASCE 7-10

2
Prediction... ASCE will issue an addendum to the 7-10 code:

Under Office Live Loads:

Due to the increased weight of design codes, structural engineering offices shall now be designed for a live load of 100 psf.

RE: ASCE 7-10

plus....
Due to the increased loads of some employees....
never mind, maybe that's jut here....

RE: ASCE 7-10

It has been pointed out before that "they don't build them like they used to" because all the old stuff that was underdesigned collapsed, and what we're left with is the overdesigned stuff.

RE: ASCE 7-10

The wind load provisions are written by academics who view practicing structural engineering as a trade, like plumbing.  Our profession is led by the nose by people like this.  

Performing an overly complicated code wind analysis that jibes with some multi-year PhD dissertation based on wind tunnel experiments is "putting lipstick on a pig" if we do not know the real wind speed data beyond two significant figures.

 

RE: ASCE 7-10

When ASCE 7-98 came out (either the first really stinky wind provisions or the first to be adopted by IBC), I went to a seminar by the late James Delahay on wind loads.  I posed the exact question that everyone in this thread is asking, "Why do we need an overly complicated wind code when UBC had one page on wind and everything is working just fine?"
His answer was that even though the earlier codes were adequate, we now know more about corners, eoverhangs, etc. and we need to implement this knowledge.  His next statement was that since everyone has access to computers now, more complicated and refined analysis could be performed.
Anyway, that's the mindset of the guys and gals that write codes.  Accuracy is more important the ease of use.   Get a bigger computer.   

RE: ASCE 7-10

Jed/Sundale, I hear you.

Perhaps I'm on my own island, but my company works on oil production facilities and mining and other industries.  These are things that mean $1,000,000 a day to the owners.  Throwing a little more steel at a problem QUICKLY outweighs the need to save 5% steel weight.  Opening facilities a week earlier is much preferred.

I'm OK with complicated and precise codes if only there were quick and conservative alternatives. The madness has got to stop.

 

RE: ASCE 7-10

We need to seriously start a movement towards simplification. I am finishing up graduate studies now and it is only getting worse from the academics perspective. Few if any Professors seem to have any practical experiences, if you even ask a question that has practical meaning you are wisked away to the land of  wind tunnels and academic papers. This is not good, as most younger students cannot find jobs and are going to straight to grad school it may become worse as now they have an additional 2 years of indoctrination. (Disclaimer - I come from the land of ME's so my initial education lacked much of the strict adherance to various codes.)

In practice, I agree with jsdpe25684, time is now more important than ever. We need clear and concise methods to arrive at solutions so we can spend time actually framing the problem and developing a proper solution. A well devised scheme will save more money in construction and material than any computation with 3 significant figures.

Computers, if anything, can tend to slow us down as we believe we can perform a more rigorous analysis than justified. Obviously computers have use, however, in terms of the codes they offer us little benefit. We now have the ability to quickly analyze 5 limit states and 20 load cases, however, how many engineers can really comprehend  such a matrix of results?  

RE: ASCE 7-10

This whole revisions is terrible. I have never read any document that is so poorly written and unclear. Hundreds of pages of data in a code does not help anyone.
All it seems to be doing is making the analysis of structure more complicated.  

RE: ASCE 7-10

I feel your pain!  My thoughts posted in the thread #507-272042 "ASD Steel Construction Manual," by Jambruins, 13MAY10, apply here too.

Between the bunch of us, if we bought only a few copies and critiqued them right here we would discover that they really offer nothing new or better, just a complicated new reformulation.  Then talk to your legislators, and building officials, at the state, county and city levels, wherever the adoption decision is made.  Their stock in trade is nit-picking on minor code details, and yet, the ones that I have talked to are almost as overwhelmed and frustrated as we are.  They can't keep up with it either, and still get any work done.  If we explained our position, and reasoning, to them, they might decide the new edition isn't worth adoption, in which case we wouldn't need to buy it.  We do probably have to show them that the new version offers no improvements in safety or economy, because that is not normally what they do, without some guidance from practitioners.

For starters, we should just quit buying every damn new edition of all of the codes and all of the new computer programs.  We pay a premium for all that crap and all of the new bells and whistles really don't improve our lives or give us better answers, results or designs or really make any of us better engineers.  This just keeps enriching the producers of this more and more complicated crap, in effect encouraging them to continue.  And each time, we have to stop production and relearn to use this new fangled system or code.
 

RE: ASCE 7-10

This is an opinion from afar, but the Aust wind code is more advanced than the American. From the news I would say in hurricane area's this is important. I am yet so see a city pass the hurricane test without damage to new buildings.  

An expert is a man who has made all the mistakes which can be made in a very narrow field

RE: ASCE 7-10

I was fortunate enough to attend an IBC seminar in which SK Ghosh spoke about the new changes to the 2010 IBC.  What a mess!  Here in Hawaii, only Oahu is on 03 IBC, and some of the other islands are on as old as 1991 UBC!!!...That's all going to change in about a year to 06 IBC for the state.  Then on our way up the IBC chain.

Im getting very frustrated at the concrete anchorage that we have to design for!  It seems like every successive code allows less and less load for anchors in concrete!  And you think engineers are not exactly the favorite around jobsites now!

And to follow up with vandede427, we actually are becoming more and more like lawyers, as we spend about 90% of our time reading code to make sure we cover our tails, 5% in acutal design, and the last 5% on these forums making sure we did the 95% of our job right!..haha...The only thing separating us from calling ourselves lawyers is the fact that we have an ethical responsibility to keep in mind while designing (just kidding..sort of).

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