Pushover Analysis of Partially Strengthened Column Structures on an Existing Multi-story Building

¹ Department of Civil Engineering, Universitas Islam Indonesia, Indonesia
² Alumni of Master Program in Civil Engineering, Universitas Islam Indonesia, Indonesia
³ Department of Civil Engineering, Muhammadiyah University of Yogyakarta, Indonesia

^* Corresponding author: m.teguh@uii.ac.id

Abstract

A pushover analysis was conducted to evaluate structuralperformance of an extended building structure subjected to simulatedseismic loads. The Inna Garuda Hotel was selected as a building object ofthis research focusing on the extension building only. This 7-storyreinforced concrete building has been functioned as a hotel building in theYogyakarta City of Indonesia for over 30 years. Preliminary results of thisanalysis indicated that the performance level of this building wascategorized as an immediate occupancy (IO), however, the plastic hingeson the slim column structure components occurred. Given this condition, the structure of the building does not fulfill the concept of a strong columnweakbeam (SCWB). The research objective is to follow up on thepotential of building collapse due to the column structure weakness byconducting a research on the strengthening of slim column elements. Apushover analysis was carried out using ETABS software. A strengtheningtechnique was adopted by enlarging the dimensions of the slim columngradually. In this study, the slim column was enlarged up to 300/650 mm(KJ-P5 model). The pushover analysis results of the KJ-P5 model haveshown the drift ratio is less than 1.0% for the four directions of thepushover with the level of immediate occupancy performance (IO). Referring to the recent building condition, the strengthened slim columnsdo not seem significant damage to the structural components of thebuilding resulting in a fulfilling of SCWB concept, where a similarcondition on their strength and stiffness as before the earthquake occurs. The results of the plastic hinge locations, as well as the performance levelsof the indicated slim columns in resisting overall structures, are extensivelydiscussed in this paper.