Effect of the vertical earthquake ground motion on seismic behaviour of reinforced concrete buildings

In this study, the effect of vertical earthquake ground motion on the seismic performance of reinforced concrete structures have been investigated. In the first stage, two different soil classes have been selected and elastic spectrum graphs have been created. Four different scenarios have been created by assuming that selected soil classes was close and far from the fault, and earthquake acceleration records have been determined for these scenarios. In the second stage, reinforced concrete building models with and without irregularities in plan and vertical, seismic isolation and inclined beams have been created, provided that the plan lengths and number of floors are the same. Using structural software based on the finite element method, building models have been analyzed using linear and nonlinear time history methods. When an earthquake occurs, buildings with the same structural features can be affected differently. In addition to the distance of the building from the fault , soil properties also play a role in determining this difference. In addition, the effect of vertical earthquake ground motion on the seismic behavior of structures is also an important parameter. Considering all these issues, scenarios have been prepared in which these parameters were taken into account in the thesis study and the seismic performance level of the six building models created have been examined comparatively. As a result of the analyses, it has been numerically determined that the vertical component of the earthquake significantly increased the column axial forces, base overturning moments, vertical accelerations, isolator forces, vertical displacement values and internal forces of secondary beams. These increases occurred at higher levels in the presence of structural irregularities. The analyses have shown that if the structure is located within the boundaries defined as a near fault, it would be a safer approach to perform analysis in the time history , regardless of the structural system of the structure. Limiting the facade length/height ratio of the structure for overturning safety depending on the distance of the structures to the fault and analyzing it without applying the earthquake reduction coefficient will make an effective contribution to the literature. Determining the limit value condition for vertical acceleration in base-isolated structures. As can be seen from the analysis results, the vertical component of the earthquake has a more comprehensive and significant effect.