Structural Assessment Considering Architectural Constraints with Seismic Retrofitting

Abstract

The Kingdom of Saudi Arabia is located in a low to medium earthquake zone. Therefore, the inclusion of seismic loads in building design was limited to specific building structures such as highrise and midrise in the past decades. Recently, the development and adoption of the Saudi Building Code (SBC) and the experienced seismic activity at many regions in the Kingdom necessitate detailed seismic design considerations for all buildings. Given this, the current work initially emphasizes assessing structural grids obtained from an architectural plan for an existing building in AL Madina. Then the structure has been analyzed critically in such a way to reduce columns and simplify the structural grid. Also, the orientation of columns has been modified to obtain structure symmetry keeping in view the architectural constraints. Two cases have been developed initially: flat slab and solid slab and designed to withstand gravity loads using Saudi Building Provisions. These cases are analyzed for the seismicity of the Medina Region. Since Medina is less prone to seismicity, the building withstands the lateral load calculated based on static analysis. To assess these buildings for stronger earthquakes, we increased the applied load to assess their capacity. Since both the proposed cases fail to withstand the increased seismic load, a bracing system has been introduced at the locations where it does not disturb the architecture of the building. It was observed that introducing bracing improves the performance of the structures. Therefore concluding that complex structural grids schemes can be simplified, regularized, and economized as well. In addition, bracings provide an easy technique to retrofit already existing RC buildings.