No. It doesn't have anythig to do with the quake going in 2 oposite directions. When i wrote twice, i ment in 2 steps, and that aplies only to quake loads. I was wondering if the quake load is triangular distribution of accelerations, why is it analysed in 2 DISTINCT steps? Even more, in a nonlinear analysis what is the relation between the first step and the second, because some times only the first step converges.
