Reinforced concrete (RC) wall structures are generally relied to perform adequately in resisting the lateral forces during strong earthquake ground motions. However, recent earthquakes have indicated that several RC structural walls were damaged or failed because of the deformation compatibility issues between the structural walls and secondary gravity systems. This failure mode is caused by interaction between the structural walls, floor systems and gravity columns under the severe earthquake actions. Hence, in order to predict the inelastic response of such structural systems under seismic loads, the hysteretic response of critical zones in structural walls and their interactions with other structural components should be accurately described by reliable numerical models.

A review of available literature confirmed that the interaction mechanism between the structural walls with neighboring structural subsystems is not yet well understood, particularly in the nonlinear response range. The research presented in this Thesis seeks to investigate the interaction mechanism between the structural walls, floor systems and gravity columns in multi-story shear wall buildings. The consequences of such interaction is also explained, which raise some concerns regarding the reliability of current design code provisions.

A numerical modelling approach is developed in this research, which is capable of successfully capturing the dynamic response of multi-storey structural wall systems under ground motion excitations. Experimental results of scaled isolated RC wall specimens and a full-scale multistorey RC wall system tested under static and dynamic loads are used for verification of the adopted modelling and analysis approach. The mechanism of three-dimensional spatial interaction between the structural walls, floor systems, and gravity columns under in-plane static and dynamic loadings was scrutinized by using the validated numerical model. The main parameters controlling this interaction mechanism are identified to be the flexural/torsional stiffness of the floor systems, the bay length between the walls and gravity frames, and the wall height, and the design base rotation.

Thus, this thesis reports the insight gained into the nature of this interaction through an extensive numerical analysis conducted using a verified and validated constitutive shear wall model employing multilayered shell elements. Several important aspects of this interaction in typical multi-storey shear wall buildings have been addressed in this Thesis. For example, based on an extensive parametric analysis of multiple case study shear wall buildings, typical values of system overstrength factor have been proposed for design of shear walls. Using the proposed system overstrength factors in capacity design of structural walls improves the seismic performance of RC shear wall buildings. Additionally, the impact of three-dimensional interactions on the amount of the axial forces in the gravity columns and shear walls is also examined in this Thesis. Finally, a practical approach for appropriate modelling of structural damping in nonlinear dynamic analysis of ductile walls is recommended.

The proposal of a simplified method for the estimation of system overstrength factor (caused by the spatial vertical interaction) in multi-storey structural walls is another outcome of this Thesis. The proposed simplified method is found to be reasonably accurate when compared to the numerical analysis results.