Kramer & Lindwall evaluate how using 1D vs 2D vs 3D ground-motion inputs affects Newmark displacements. They show displacement predictions vary dramatically with motion direction, especially at high yield accelerations.
Dimensionality and Directionality Effects in Newmark Sliding Block Analyses
S. Kramer; N. Lindwall · 2004 · Journal of Geotechnical and Geoenvironmental Engineering
