The comparison of X-braced frame and moment frame on structural building (case study: government office of North Toraja, South Sulawesi, Indonesia)

The seismic force can damage the building and harm the occupants. Therefore, its structure needs to be designed seismic-resistant. One of the essential things in seismic-resistant building is the effect of lateral force to its structural rigidity. It can be improved by using the lateral resistant element such as bracing and shear wall. The lateral element used in this study is concentric X-bracing. This study conducted an optional structural model of the office of North Toraja Regent, Panga, South Sulawesi. The building was originally analyzed as a whole unit structure, but it has already rotated in its first mode shape due its irregularity. The comparison analysis is conducted by using the same existing structure configuration, except with the addition of X-bracing. The analysis results of the dynamic response are the fundamental building period, mode shape, base shear, lateral displacement and P-delta effect. The fundamental building period using X-bracing is smaller than moment frame building. It indicates that the use of X-bracing lead to the stiffer building. The use of the X-bracing results in a larger base shear value than the moment-frame building. The difference in base-shear between X-braced frame with moment frame is about 211.77% and 212.10% for seismic force with X-direction and Y-direction respectively.