Study the effect of the type of soil and soil layer thickness on the dynamic response of the structure during the earthquake

It was found in this research that the seismic response of the structure increases with the decrease in the shear waves velocity in the soil, and the seismic response of the structure increases with soil layer thickness between the foundations of the structure and bedrock depth.

3D-FEM-Analysis on the Seismic Behavior of Foundation Piles and Soil Structure Interaction

This research deals with the study of the behavior of piles under the influence of seismic loads through (3D) modeling using FE-Method-program (ABAQUS) with special reference to the most important parameters affecting the displacements and internal forces generated in piles. This study has been completed in two phases: the first phase is a case study of the single Pile (reference case), where a study of the behavior of a single pile assigning structure is modeled with a degree of freedom. The parametric study results show that the presence of structure causes the application of a large load in the upper part of the pile resulting from the impact of inertia dominating the kinetic effect. The forces of inertia increases with the increasing mass of structure, and when the frequency of structure nears the frequency of seismic load. The second phase deals with the study of the situation of the group of piles, where the study handles the effect of a number of piles, piles spacing, and locations on the internal force and displacements generated in the piles. The parametric study results have shown for this phase of this research that an increase the number of piles in the group causes a significant increase of internal forces generated at the top of the pile and a slight decrease for those forces in the central part of the pile, that seismic loads are not distributed equally for all piles, and that corner piles are subject to greater loads while mid. Piles are subject to less load.

"Nonlinear Static Analysis (push-over analysis) and its Applications on the Effect of Improving Soft Soil on Increasing the Performance of Seismic Resistance Concrete Frame"

This research includes the procedures of applying the nonlinear static analysis (pushover analysis) on seismic resistance concrete frame systems by modeling the foundation system (soil + footing) down the structure as an elastic springs and rocking stiffness and comparing them with premise of fixed support in terms of the deformation and displacement, load and stress distribution in frame elements and accordingly clarifying the effect of improving soil on foundation system stiffness and on the responding of frame to lateral loads which helps in moving the structure performance from low level to a higher level that we need from structure to reach following the design strategy that we choose for the structure.