Hi Rock09,
I located Taiwan, we ever meet same question as yours. We solve the problem by Plaxis 3D program to realize the different of 2D and 3D effect. Our result indicate the 2D is more conservative than 3D. So we adopt 2D result for designing. But we found another interesting question...
Does any one know why we use 5% strength of reinforcement, not 1% or 3% strength of reinforcement to determine the internal stability of reinforced slope?
Please kindly help me.