| Author |
Message |
Stephen J. andros
Junior Member
Username: grenspecwriter
Post Number: 2
Registered: 01-2006
| | Posted on Wednesday, March 01, 2006 - 04:27 pm: |    |
We're updating our Guide Specs and discovered that we reference Seismic "zones" (from the old UBC)... but HOW does one address the seismic requirements under the 2003 IBC? (It's REALLY complicated.) Any suggestions? |
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt
Post Number: 628
Registered: 03-2002
| | Posted on Wednesday, March 01, 2006 - 07:04 pm: | |
Speak with your structural engineer. I agree that it has become WAY to complicated than just looking on a map.
Luckily we do projects in the Puget Sound area and it is predominately Seismic Design Category D. But I still ask my engineer for confirmation. |
Doug Brinley AIA CSI CDT CCS
Senior Member
Username: dbrinley
Post Number: 173
Registered: 12-2002
| | Posted on Wednesday, March 01, 2006 - 07:09 pm: | |
Bruce Erickson at KPFF in Seattle has recently managed an 80 foot deep 'cut and cover' tunnel down Pike St. He is an expert as far as application of the IBC vs. 'state of the art' seismic design. Let me know if you want to discuss w/Bruce. |
Mark Gilligan SE, CSI
Senior Member
Username: markgilligan
Post Number: 59
Registered: 05-2005
| | Posted on Thursday, March 02, 2006 - 02:45 am: | |
I agree, talk to your Structural Engineer. There are many engineers out there who can help you.
I believe that we are past those days where we addressed the specification of seismic design of components by just giving the Contractor the seismic zone factor. Today the specifier needs to be more aware of the provisions in Chapter 16 and 17. Preferably you should involve the Structural Engineer as an active participant in the process as opposed to a passive supplier of information.
With the increased complexity of the Code your engineer may need to spend some time working with you to get the specification language up to date. Since it is likely that many of your questions relate to systems that are not in his scope of work your engineer may not have budgeted anything for this time. |
Doug Brinley AIA CSI CDT CCS
Senior Member
Username: dbrinley
Post Number: 174
Registered: 12-2002
| | Posted on Thursday, March 02, 2006 - 03:24 pm: | |
I agree with Mark and further suggest you consider that most structural designs exceed the 'minimum' seismic design loadings required by the IBC, when the designs are done correctly. For a surprising number of (most/many?) structures, wind loads govern the lateral design. |
Stephen J. andros
Member
Username: grenspecwriter
Post Number: 3
Registered: 01-2006
| | Posted on Monday, March 06, 2006 - 03:54 pm: | |
OK... I think that what we'll probably end up doing is to develop a standard "blurb" that states "in accordance with the requirements of the applicable provisions of the IBC" to cover seismic in a general way within the specifications. We recognize that the General Structural Note probably address these requirements and that the specifications really don't need to concern themselves with these requirements. |
Mark Gilligan SE, CSI
Senior Member
Username: markgilligan
Post Number: 61
Registered: 05-2005
| | Posted on Tuesday, March 07, 2006 - 02:08 am: | |
It is my opinion that there is no need for a general statement in the specifications regarding seismic design. We do need to address specific requirements related to seismic concerns but these provisions will normally be addresssed in the individual specification sections.
Often times we will require the Contractor design components of the building which may be subject to seismic loads. In such cases we need to provide him with certain pieces of information so his engineer can perform the required calculations. This is what I thought the original posting was about.
I have operated on the premis that in general it is inappropriate to tell the Contractor that he should comply "with the applicable provisions of the IBC". In the BOCA Code there was actually a code provision that prohibited such statements. We should point the Contractor to the specific code provisions.
Unless we have specifically asked the contractor to provide engineering services we should only reference those code provisions that do not require the exercise of engineering judgement or calculations. |
Phil Kabza
Senior Member
Username: phil_kabza
Post Number: 158
Registered: 12-2002
| | Posted on Tuesday, March 07, 2006 - 02:36 pm: | |
I'm recalling the blank looks I received from the installers of some library stack units recently when I noted that they hadn't submitted shop drawings that included the attachment methods they proposed to use to meet seismic requirements.
I think Mark is quite correct. The project SE of record establishes the Seismic Design Category for the project. Our individual specification sections reference that information for the development of architectural component anchoring requirements when carried out by the contractor's engineer. That follows the general practice of the designer of record establishing the performance requirements, and the delegated designer using those performance requirements to establish product-specific requirements. |
Ralph Liebing, RA, CSI
Senior Member
Username: rliebing
Post Number: 329
Registered: 02-2003
| | Posted on Tuesday, March 07, 2006 - 03:07 pm: | |
Isn't the ability to delegate design [as noted in AIA A201] part of the seismic equation,as Mr. Kabza mentions?
We have a Div. 01 Section specifically written to set this process out,and in there we list the applicable building code and the Seismic Design Category for the project [IBC provisions} as the Desing Criteria. The individual tech Sections [incl. MEP] reference this Section and note items that may require seismic consdieration/ design. It is then left to the contractor to hire a professional [engineer or architect] who knows the area and the requirements to select proper devices or designs the systems required.
Our structural department does the actual design of the bulding structure to the same criteria. |
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