Studi Komparasi Sistem Steel Frame Tube dengan Sistem Steel Braced Tube menggunakan X-Brace

Abstract

Population development in Indonesia is not parallel with land avaibility, therefore multi-story buildings are more developed. The tube system is commonly used in tall building structures, such as the Steel Frame Tube (SFT) system. However, due to the shear lag phenomenon, the axial stress distribution in the angular perimeter columns is greater than the other perimeter columns. This was overcome by using the Steel Braced Tube (SBT) system which can make the perimeter of the building more rigid by using diagonals on the entire face of the building. This study examines the elastic and inelastic responses of a 12-story building using both structural systems with spectrum response, pushover, and time history analysis with records of El-Centro 1940, Kobe 1995, and Denpasar 1979 ground accelerations. Based on spectrum response analysis results, stiffness in the SBT system is higher thus the drift of the system is smaller. Based on pushover analysis results, the SBT system is 157.101% more ductile, although the deformation of the SFT system is larger. This is because the first hinge occur in bracing elements that are designed as fuse elements. Based on time history analysis results, drift of the SFT System is greater for the three records of ground acceleration but remains of lower value than the drift boundary. Based on the results of nonlinear analysis, both structural systems have Immediately Occupancy (IO) performance. It can be concluded that in addition to reducing the phenomenon of shear lag, the SBT system has better elastic and inelastic response.