Differential settlement between foundation units of a multi-story structure has been responsible for serious damage to buildings, and often catastrophic failure and loss of life. The dynamic changes in the loading conditions of the structure, and the variability of the underlying ground due to environmental changes, are causing the undesirable differential settlement, which is manifested in the form of additional stresses in beams, columns and distortion of the structure elements.  
The structural response to the differential settlements depends on the type of the structure (concrete or steel), type of beam-to-column connections (rigid or semi-rigid), the number of floors, height of the floor and the spans of the beams in the building. 
Due to the complexity of the problem, and the enormous amount of the governing parameters, research in this field is lagging behind, which further attributed to the lack of communication between structure and geotechnical engineers. Yet, the current design codes of structures do not include these additional stresses. Engineers are dealing with this problem by using empirical formula, recommendations given in the literature, or by increasing the factor of safety of the superstructure.  
This study presents experimental and numerical investigations on the problem stated. Experimentally a four-floor aluminum structure was developed in the laboratory. The model was instrumented to measure the stresses and strains induced in beams and columns as a result of the settlement of a center, edge and corner column respectively, which are the critical columns in the structure. Numerically a 3-D finite Element model was developed using the commercial software “ABAQUS” 
After being validated with the present experimental results, the numerical model was used to analyze a 9-floor steel structure and to conduct a parametric study. The results are presented in the form of stress distributions in the structure, the role of beam-to-column connections and guideline for the design of these structures.