Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: ASD load combinations in UBC '97, vol. II

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Do not divide E by 1.4 when using Chapter 22, Division IV.  UBC, Chapter
22, Division IV are NOT ASD provisions.  They are Strength Design
Provisions to use in adddition to the ASD design of the members that you
have chosen to do.

Rick Drake, SE
Fluor Daniel, Aliso Viejo, CA

*******



                                                                                                                   
                    "Vasu, Ravi"                                                                                   
                    <Ravi.Vasu@jaco      To:     seaint(--nospam--at)seaint.org                                                 
                    bs.com>                                                                                        
                    10/11/02 06:58       cc:                                                                       
                    AM                                                                                             
                    Please respond       Subject:     ASD load combinations in UBC '97, vol. II                    
                    to seaint                                                                                      
                                                                                                             ..... 
                                                                                                                   




I have two questions(UBC 1997, Vol. 2) here.
Thanks in advance.

1  a. Refer to UBC '97, section 2213.5(Allowable stress
design(ASD)), pg. 2-255(column requirements)
The load combinations have 'omega' to check column compression &
tension.  AISC, '97 'seismic provisions for structural buildings',
pg. 135(section c4.1) says that for all Allowable stress design,
E(from UBC) should be divided by 1.4.
So, in the above UBC section 2213.5, I think, from section
1630.2,(to calculate Pe) should be divided by 1.4(since that section
in in ASD).  In fact, in LRFD(section 2211.6.4), for the same check
on columns, we do not need to divide E by 1.4(from AISC on '
seismic...).

b. Similarly, for bracing connection design
and moment connection(UBC section 2213.8.3.1 & 2213.6 under "ASD"-
pg. 2-258 & 2-256), in the combinations with 'omega' times the
'design seismic force', the E (from section 1630.2 procedure) should
be divided by 1.4 or not?.  Pl. verify.

2.  In UBC section 2213.8.3.1(pg. 2-258), the forces for bracing
connection has 'The maximum force that can be tranferred to the
brace by the system'(3 rd item).  Does it mean, the load
combinations to use to find the force is from section 1612.3(pg.
2-4) ONLY?  or any other load combinations required?    If the load
combinations are only from section 1630.2, then forces from items 1
& 2 in section 2213.8.3.1 may not GOVERN at all.?

I appreciate your time & response very much.

Thanks

Ravi
Telephone:832-351-6856


======================================================================================

NOTICE - This communication may contain confidential and privileged
information that is for the sole use of the intended recipient. Any
viewing, copying or distribution of, or reliance on this message by
unintended recipients is strictly prohibited. If you have received this
message in error, please notify us immediately by replying to the message
and deleting it from your computer.

==============================================================================



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********






-----------------------------------------------------------------------------------------------------
The information transmitted is intended only for the person
or entity to which it is addressed and may contain confidential
and/or privileged material. If you are not the intended recipient 
of this message you are hereby notified that any use, review,
retransmission, dissemination, distribution, reproduction or any
action taken in reliance upon this message is prohibited. If you 
received this in error, please contact the sender and delete the 
material from any computer.  Any views expressed in this message
are those of the individual sender and may not necessarily reflect 
the views of the company.  
-------------------------------------------------------------------------------------------------------


******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********