Comparative Analysis of Steel Buildings with and Without Bracings in Nepal
Keywords:
Steel building, Bracing, Seismic design, Storey drift, Base shear, Fundamental time periodAbstract
The past few years have seen a remarkable increase in the construction of steel-framed buildings in Nepal. This has provided much-needed architectural relief to urban centers full of RC buildings. The main reasons for this current proclivity towards steel buildings can be attributed to the faster time of the erection of steel buildings, its lightweight resulting in easier handling and cheaper transportation, and lower material cost. However, because of its flexible nature, an unbraced steel building will have higher storey displacement when compared to RC buildings. For mid-rise and high-rise buildings, the steel frames need to be equipped with braces to keep the storey drifts and displacements within acceptable limits. This will result in a stiffer building and hence result in increased base shears and bending moments. This change in base shears and storey drifts along with the building’s fundamental period may not be similar for different positions of braces despite the use of similar bracing sections. This paper aims to find such differences, if any, to aid designers in selecting an optimum position for braces while designing steel-framed buildings.