A cooperative study is developed between University of Missouri and the National Chungkung University of Taiwan to develop axial-rocking (ARR)) spectra, use the ARR spectra with other existing spectra of lateral, verical, and lateral-torsional motion to study the effect of interacting ground motions on three-dimensional building systems, conduct experimental study of the hysteretic behavior and stiffness reduction of reinforced concrete (RC) shear walls without boundary columns aand with various height-and-width ratios (0.5 to 3.0) subjected to monotonic models for predicting the inelastic behavior of buildings systems, and study the damage of RC shear wall systems through analysis and expermental observations.