You can always consider the "bonehead" approach.
Calculate the length of each stringer. Apply a uniform load (DL + LL) to
each. Since they're different lengths, deflections will be different, so
you might check maximum cross slope of a tread (at mid-height if simply
supported; at top if cantilevered).
If stresses are conservative, deflections within limits, and cross slope
modest, you're there. You can do all the verifying analysis you want, but
if everything checks out the simple way, you should be good to go.
Recognize that we, in Florida, aren't much troubled by seismic.
Fountain E. Conner, P.E.
Gulf Breeze, Fl. 32561
> From: Brad Friederichs <brad(--nospam--at)vesolutions.net>
> To: SEAOC <seaint(--nospam--at)seaint.org>
> Subject: Curved Stair
> Date: Thursday, June 01, 2000 6:13 PM
> The stair is 6'-6" wide with outside radius of 13'-6" and inside radius
> 7'-0". The stringers are made from C12 and the risers and treads are
> closed system welded to the stringers.
> The arc is 90 deg.
> Are there design charts or tables that have already been prepared for
> of this type? If not, are there shortcuts to design other than doing a
> finite element anaylsis.
> I'm doing the structural design.
> Thank you for your assistance.
> Brad Friederichs
> VE Solutions, Inc.
> (916) 505-0519