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