Evaluation of Floor Addition Effects on Building Structure Using SAP2000 Student Version (Case Study: SD Lab School UPI Serang)

Abstract

The increasing number of students drives the need for vertical development of school buildings. This study evaluates the capacity of the existing structure to accommodate additional floors, focusing on the maximum allowable number of floors, structural response, and the feasibility of developing a growth-oriented building. The analysis was conducted using SAP2000 v22, employing equivalent static and response spectrum methods in accordance with SNI 1726:2019. Four scenarios were examined, including the existing two-story condition and the addition of one to three floors. The parameters assessed include stress ratio, internal forces, deflection, and inter-story drift, with load references based on SNI 2847:2019 and SNI 1727:2020. The novelty of this study lies in the incremental scenario analysis, which provides a progressive understanding of structural behavior up to its maximum safe limit. This approach is rarely applied in similar studies and offers deeper insight into the actual capacity of growth-oriented buildings, particularly in educational facilities. The results indicate that the existing structure can safely support the addition of one floor, resulting in a total of three floors. Adding floors significantly affects structural performance, as reflected in increases in stress ratio, axial forces, bending moments, and shear forces. Deflection and inter-story drift also increase, yet remain within allowable limits. Evaluation of the structural capacity shows that with the addition of two or three floors, some elements experience excessive axial and shear forces, indicating that the existing structure can no longer safely accommodate additional loads without reinforcement. Therefore, the existing building is deemed suitable for development up to three floors, but further additions are not recommended without strengthening the main structural elements.