Unless the book prescribes the equation, I would think that the
curvature would be R=EI/M and you could start with As=M/Fs(j)d solving for M
using the min. code requirement for As. If you use f(Es,Ec) then "N" should
be included too.
From: Jake Watson <jwatson(--nospam--at)inconnect.com>
To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
Date: Sunday, May 14, 2000 11:19 AM
Subject: Concrete Shearwalls
>OK, this one will require some thought....
> Has anyone gone through the concrete shearwall provisions in detail? My
>question is this. If you follow the code, you are allowed to assume
>yield curvature as Ec/(Length of wall). This amounts to assumed maximum
>concrete strain (0.003) divided by wall length. (Sorry - can't write the
>greek letters). Two questions come from this:
>1) Is the point to find the concrete or steel yield point?
>2a) If it is steel, shouldn't the curvature be (Es+Ec)/(Length of Wall)
>2b) If it is concrete, shouldn't the curvature be Ec/C`u?
>My thought is this, if the wall is pushed into the plastic region we
>should be providing boundary confinement. The elastic region would end
>at one of the two states listed in 2a or 2b. The limit state listed by
>the UBC is non conservative if my assumptions listed in 2a and 2b are