Re: Seismic design of staircase in California

Rajendran,

Are you asking about the overall staircase as a structure or are you asking about a staircase within a structure?  If you are talking about a steel braced frame or moment frame structure with a staircase inside then the overall structure would be likely a non-building structure similar to a building in which case you can use either Table 15.4-1 or Table 12.2-1.  If you just designing the staircase (i.e. stair stringers and attachments) then you would use Table 13.5-1.

Thomas Hunt, S.E.
Fluor



From:        Padmanabhan Rajendran <prajendran@ymail.com>
To:        seaint@seaint.org
Date:        11/29/2010 11:00 AM
Subject:        Re: Seismic design of staircase in California

---

Tom, It is a stand alone structure. If I used Chapter 13 procedure, will it pass through the Permit Agency's scrutiny? Thanks. Rajendran --- On Mon, 11/29/10, Tom.Hunt@fluor.com <Tom.Hunt@fluor.com> wrote: From: Tom.Hunt@fluor.com <Tom.Hunt@fluor.com> Subject: Re: Seismic design of staircase in California To: seaint@seaint.org Date: Monday, November 29, 2010, 4:20 PM Rajendran, Unless your staircase is part of the overall lateral force resisting system of the building it would probably be more appropriate to consider it a non-structural components and use ASCE 7 Chapter 13 for your seismic design forces (i.e. Fp forces). Thomas Hunt, S.E. Fluor From:        Padmanabhan Rajendran <prajendran@ymail.com> To:        seaint@seaint.org Date:        11/29/2010 08:13 AM Subject:        Seismic design of staircase in California I am designing a steel staircase located in South Long Beach, California. It is about 22' tall laid at about 40 deg to horizontal. To estimate seismic loads on the structure, I am considering it as a non-building structure subject to the sections of Chapter 15 of ASCE 7 (2005 edtition). There are 2 tables in this chapter to determine "R" and "Omega 0": Table 15.4-1 for nonbuilding structures similar to buildings and Table 15.4-2 for nonbuilding structures not similar to buildings.  I think the staircase would be classified under Table 15.4-2 as "All other self-suppoting structures, tanks or vessels not covered above or by reference standards that are similar to buildings". Under this classification R = 1.25 and Omega0=2. Is my assumption correct? If not, what will be the accepted method? Thanks. Rajendran ------------------------------------------------------------ The information transmitted is intended only for the person or entity to which it is addressed and may contain proprietary, business-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.   ------------------------------------------------------------

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