| Title |
Seismic Performance Evaluation of Highrise Steel Concentrically Braced Frames |
| Keywords |
Highrise Building ; Wind Design ; Concentrically Braced Frames ; Soil Site ; Seismic Performance Evaluation |
| Abstract |
This paper aims to investigate the possibility of elastic or limited ductility seismic designs for highrise buildings through modal response spectrum analysis using elastic seismic design spectrum of various soil sites per KBC2009 as input ground motions for the potential earthquakes which wind-designed highrise steel concentrically braced frames can experience during the life cycle of highrise buildings under strong wind zone and low seismicity such as Korean peninsula. From wind design procedures, it was verified that substantial system overstrength to act as the potential factor increasing the possibility of elastic seismic design for highrise steel concentrically braced frames is flowed in. All analytical models except slenderness of 4 in SE soil site were able to resist elastically against SLE, while it was found that the models having slenderness greater than 6 in SA soil site and slenderness of 7 in SB soil site can behave elastically against MCE. Flange columns, which are the force-controlled members, showed the response of immediate occupancy level against SLE in all soil sites and MCE in SA and SB, when the slenderness is higher than 4. Deformation-controlled action of diagonals with slenderness above 4 were forecasted immediate occupancy level in all soil sites for SLE and immediate occupancy and life safety levels in most of the soil sites for even MCE. Moreover, high-rise steel concentrically braced frames with slenderness of above 4 were showed the performance level of immediate occupancy for SLE in all soil sites and ,for even MCE, models having slenderness of greater than 4 in SA soil site and slenderness of 7 in SB soil site were also presented immediate occupancy level according to seismic performance evaluation standard of system level. Finally, it was recognized that the elastic design of wind-designed highrise steel concentrically braced frames, that is, seismic design using the response modification factor of 1 is available in all soil sites for SLE and SA and SB soil sites for MCE under strong wind zone and low seismicity. |