Kinerja Struktur Baja dengan Sistem Rangka Pemikul Momen Khusus yang Menggunakan Reduced Beam Section dalam Dua Arah Orthogonal

摘要

Many steel structures collapse during the 1994 Northridge Earthqkuake due to poor beam-column connection. Structures fail to maintain strong column weak beam condition, leading to unsafe collapse mechanism. The use of Reduced Beam Section (RBS) is able to force the inelastic deformation away from beam-column connections. The method reduces beam flange area in order to reduce the beam moment capacity at the interface of the column. udThe previous study on steel special moment resisting frames (SMRF) using RBS in their one principal axis shows that their interstory drift are larger than the limitation value defined by Vision 2000. The structures use wide flange section for their colums. Continuing the research, this study is aimed to check the performance of steel moment resisting frames using RBS in their two major orthogonal axes. In order to reduce the excesive interstory drift, structures use kingcross section.udBeams and columns are design based on Indonesian Steel Code SNI 1729-02 and Indonesian Seismic Code SNI 1726-02 while the RBS’s are designed using AISC 358-05. The considered structures are 6- and 10-story office buildings consist of 5 bays with 6 meters span, located in zone 2 and 6 of Indonesian Seismic Map. Static nonlinear pushover analysis and dynamic nonlinear time history analysis have been used to observe the performance of the structures. The structures show good performance in terms of interstory drift and damage indices, and experience safe collapse mechanism. The use of RBS’s in the structures are able to maintain strong column weak beam condition. However the use of kingcross section resulting higher cost of structure than conventional SMRF which is use wide flange section as their column section. ududKeywords: Reduced Beam Section, structural performance, special moment resisting frame.ud