new aisc manual 2

[bjb]

I just saw an ad in Structural Engineer Magazine for the new combined steel manual. The cost is $175 for AISC members, and $350 for non-members. YIKES, that's pricey. Way back in '94 I picked up my green book for about $60 at my college book store. Do I wait for a revised edition that addresses typos or risk the first printing? My state is still with the 2000 IBC, and next year will be going to the 2003IBC, so legally, I guess I can still use the '89 ASD. I would rather get up to speed with the new spec however, but it is expensive! The steel manual is one of the books that I like to personally own because I customize it, and if I change jobs I need my steel book with me.

 

[UcfSE]

The 2005 specification is available for free download with commentary. It is not the Manual, but should give us an opportunity to learn the specification without having to pay out all that money before it is required.

http://www.aisc.org/Template.cfm?Se...Management/ContentDisplay.cfm&ContentID=27871

 

[whyun]

I bought my 2000 IBC back in 2000. My state has not adopted the IBC series codes yet (can you guess which?) and 2006 IBC is soon to be published. By the time we adopt the IBC, it will probably be 2003 or 2006 version. My 2000 IBC is quite new without any personal notes or highlights, yet it is obsolete.

I recommend you to ask your employer to get a copy of the new AISC manual. Make copies as needed to put your own notes/highlights. Once the model code adopts the AISC, you can purchase your own copy and gradually transfer the old notes on your own manual.

If you own your own company, I don't think $350 should be a big burden... Just my few cents...

 

[bjb]

whyun, that is probably what I will be doing, getting one through my company at first. I think that overall the cost of the references that we need is getting seriously expensive, and the costs hurt. I'm an employee, so when I buy a reference for myself at these prices it hurts. I'm an AISC member, so at least I can get it for $175. I'm also thinking about the costs of other references that I like to own personally, such as the timber manual that I also want to update.

I have downloaded the new spec, and it is basically the LRFD spec, except that instead of multiplying the nominal strength by the resistance factor you are allowed to divide by the FOS. I just have a case of sticker shock for the cost of the manual.

 

[JAE]

Your $60 manual in 1994 would cost you $76 today

(see this link for the inflation calculator: Inflation Calculator)

So $175 is definitely an increase - but it contains both ASD and LRFD, so if you multiply it by 2 - you get 2 x $76 = $152 which is comparable.

 

[bjb]

except in 1994 I was a non-member. I don't know if my bookstore would have passed on any AISC discount but I doubt it. To really compare apples to apples we'd have to know what AISC was selling the green book for back in '94.

 

[archeng59]

I saw those price differences, too. I need to buy four manuals so will become a member long enough to get the discount. wow.

how many of you will use the ASD equations in the new manual instead of using the ninth edition equations? will you change to LRFD since the new manual equations are pretty much the same between LRFD and ASD for determining nominal strengths?

 

[bjb]

I doubt I will go to LRFD because I dislike having to keep track of factored loads for strength and service loads for deflection and soil pressures. I learned LRFD in college, then had to learn ASD in practice, and I prefer ASD. I will keep my old green book around, I could see it being potentially useful to rough something out quick and then do a formal check with the new manual. Don't know if it will work out in application, but that's what I'm thinking now.

 

[archeng59]

bjb, I had the same thoughts. but with concrete design, I have a set of factored load combinations for member design and another set of unfactored load combos for service and foundation design. one concern I have is with new engineers, trying to make sure they use the proper phi or omega factors with the strength value and factored/unfactored loads. Is the new manual punishment to those of us who kept using the ninth edition instead of LRFD?

 

[bjb]

Mostly my concrete design is limited to foundations and retaining walls. Conservatively, I usually just keep track of the service load, and then multiply everything by 1.7 for my strength checks. I agree that there will probably be confusion between safety factors and strength reduction factors. Speaking of punishment, look at the LRFD example for the design of a crane girder in Design Guide 7. I will keep my green book around if for no other reason than to rough out a crane girder.

I am going to go off on a tangent now.

I wonder, what have we really achieved with the ever increasing complexity of our codes? Does having overly complicated codes that are difficult to interpret really increase the reliability and safety of structures? Instead of all of the cutting edge computations, would it be better if we could spend more time on our drawings so that they are adequately and correctly detailed? I regularly burn the midnight oil to make this happen, but I see lots of drawings by others that are very poor. Maybe if structural engineers had more time to spend on the drawings the reliability and safety of structures could also be increased. I know that my schedules and budgets have not been increasing to match the ever increasing complexity of the various codes and design standards. I'm not against progress or advancing the state of knowledge, but I think we need a reality check.

 

[archeng59]

gotta agree with you on your tangent subject. a chance for me to rant, too. we get less and less time for analysis and design, document preparation but generally, the contractor gets the same amount of time to build as he always has been given. The overall complexity of the contractor's work hasn't changed much compared to the code requirements affecting structural analyis and design. in my opinion, overall project time, from concept to occupancy is shorter, with the schedule reduction taking place during the design phase. part if this is because of design build, but some of it is because architects don't want to tell an owner the realistic amount of time needed for design. most owners, and perhaps some architects and contractors, believe that computers should allow us to reduce our design time. I think that some architects, contractors and owners believe we simply have to pick and chose components out of a catalog like architects select doors and windows. as a profession, structural engineers have done a poor job educating architects, contractors and the public about what is required for us to do our work, the importance of us doing it well and requiring that we be given adequate time to do a quality job. lots of life safety issues involved for us doing our work properly and more lives involved if we fail.

 

[chichuck]

bjb & archeng59,


AMEN brothers!!!


regards,


chichuck

 

[henri2]

Great points bjb.

I'd like to chime in with a few points/questions.

With increasing utilization of cutting edge design methodolgy, thereby pushing the envelope further, QA/QC for the structure under construction has to be taken into account in order to safeguard structural integrity.

You touched on the importance of focusing on preparation of drawingss; does AISC have a recommended standard practice for structural steel drawings?

 

[archeng59]

henri2, is it the structural engineer's responsibility to police the contractor's work and ensure that the builder constructs the facility in accordance with the CD's and his contract with the owner? if so, why? PE's accept the responsibility to police ourselves and our work. we accept the responsibility for work performed "under our direct supervision" and ensure that our work meets code. Why are we held to a higher standard than contractors? Our efforts to analyze and design using state of the art technology are wasted if the contractor is allowed to use the least expensive, and often unqualified, laborer to construct the building. It frustrates me when a contractor performs poorly and the owner blames me for not verifying that the contractor did the work properly. why are PE's letting this occur? we sign contracts with architects that state we are not responsible for means and methods or for the contractor's work, but that's what we are being asked to do repeatedly by owners.

 

[henri2]

archeng59,

Agreed means and methods is not the responsibility of the PE but QA is another matter. On many projects QA input from the RDP is now required by the IBC. It is even required on some bldgs which are occupancy classification R-3.

Essentially QA in the IBC is three-tier: building inspections Sec 109, special inspections Sec 1704, and structural observations (RAs and PEs)sec 1709.

For the RDP QA means having input in special inspections (preparation of SI program, responding to field discrepanices based on SI report etc) and performing structural observations.

Check IBC Sections 106.3.4, paragraph 3, 1704.1.1, and 1709 for responsibilities of the RDP. Another document which delves into this is ICC's Model program for Special Inspection Section II.D Duties and Responsibilities of the Design Professional in Responsible Charge.

Increasing sophistication in structural analysis and design allows for reduction in redundancies but does that not increase failure(serviceability etc) risk when consideration of the poor quality of construction you allude to is taken into account? And if that is the case does it not follow that observation of construction by the RDP will help mitigate the risk?

The assumption that a contractor will be able to fabricate a complex connection without an expert periodically verifying it is done in accordance with drawings can be risky...don't you think so?

It will not be too long when QA will be viewed as part of normal standard of care for the structural engineer and attorneys are aware of this.

 

[DRC1]

Working on he contractor end I would like to jump into this thread. I wish we could post it in the Construction Owner's Daily, if such a publication existed.I agree with bjb that making the codes more complex really has not saved the owner any significant money and distracts atention from the overall product. One of the big problems I am seeing is that either by the time we are bidding the project, the plans have just been completed on an expedited basis or they are not complete. More and more jobs are bid with plans marked "not for construction" I am really glad I am not you guys in that situation. AISC's national conference has a seminar "Purging Extra's in Construction" My suggestion, give someone a chance to finish and review a set of plans before they go out to bid.

 

[archeng59]

henri2, I'm aware of the code requirements for inspections and observations. I just disagree that it's our responsibility as the RDP to police the contractor's work. the argument made by the code writers is that the RDP is the best people to review what the contractor is doing since we know our drawings and can tell if the contractor is making a mistake. while that is true, there isn't anything to force the contractor to satisfy the contract requirements since he's liable for only one year after construction is complete. at least it's that way in Oklahoma. after that, if there is a problem it's the RDP's insurance that's on the line for problems.

DRC1 has a point that sometimes drawings are incomplete. that gets back to the comment about not being allowed enough time to do a proper job. this has happened to me too often, the drawings sent out to bid are the 2nd, 3rd or even 4th design produced by the design team because of changes by the owner. typically, the owner changes their mind dramatically without giving additional design time to accommodate the changes. Their time is money, but apparently our time is not. then the design team gets hung for change orders, too many rfi's and sometimes gets claims filed against them for a poor design job. a good architect will demand adequate time for accommodating changes, but those kinds of architects are too few.

 

[bjb]

I agree with you 100% archeng59. Something we would do at my last firm was to put a clause in our contract that said something like, "any substantial changes to the layout will result in extra services which will be billed at our hourly rates". I can't remember the exact words. On this one particular school project, we had some diagonal bracing in a wall, things were coordinated with the architect and everyone was ok with it. The layout that we were using was ok'd by the owner. After the design is all complete and drawings are out there, the owner decides that they want this wall to become a partial height knee-wall. I tell the acrchitect, since you can't have diagonal bracing in this wall anymore, we have to do some extra work and design a moment frame, which is an extra service. The architect literally freaked out and started yelling me, accusing me of providing bad service. I told him we designed once based on an approved layout, our designed was approved by you, Mr. Architect, and we weren't going to eat the costs to redesign for an owner initiated change. Fortunately, I had the support of my boss, as this wasn't the first time this particular architect attempted to get us to eat the cost of a big change. It seems like some architects don't realize that we have to have calclations for everything, and that we don't just arbitrarily throw down sizes based on a whim. This was a bad client, so we were happy to not work with them again.

I think that sometimes we are our own worst enemies, because many times we don't stand up to this. Unfortunatley, if you do, the architect or owner will get mad, and there is probably another structural firm out there who will go along to get along, and who won't sweat the details, thereby keeping the design cost low.