Seismic Performance Evaluation of High-rise Steel Diagrid Frames with Torsional Irregularity

비틀림 비정형 초고층 철골대각가새골조의 내진성능평가

This paper analyzes economics and investigates the possibility of elastic seismic design of wind-designed high-rise steel diagrid frames with torsional irregularity in Korea. To this end, high-rise steel diagrid frames with twist angles of $0^{\circ}$ (to represent regular building), $1^{\circ}$, and $2^{\circ}$ were first designed to resist wind loads. Then, seismic performance evaluation for the buildings was conducted using linear dynamic analysis. Analysis results show that total steel weights of the wind-designed high-rise steel diagrid frames with twist angle of $1^{\circ}$ and $2^{\circ}$ are about 1.14 and 1.22 times larger, respectively, than the weight of regular frame with twist angle of $0^{\circ}$. Demand-to-capacity ratio and seismic performance level present that high-rise steel diagrid frames can resist service level earthquake elastically whether high-rise building has torsional irregularity or not. For maximum considered earthquake, high-rise steel diagrid frames with torsional irregularity may be designed based on the limited ductility seismic design methodology.