Cost-Benefit Analysis of Applying SM570 Steel to Tall Buildings in Taiwan

Abstract

The cost and benefits have been analyzed of applying SM570 steel to tall buildings in Taiwan. In detail, two 40-story steel buildings are designed for the Taipei Microzonation II. One building has SN490B steel columns. The other also uses SM570 steel for the 1st -to- 14th -story columns. The stress ratios and story drift ratios are limited to 0.9 and 0.005, respectively. The drift demands are then evaluated by using nonlinear time history analyses with 14 sets of ground motions scaled to the intensity for the return periods of 475 and 2500 years. By FEMA 356, the building fragility is further assessed using the drift ratios of 2.5% and 5% for life safety and collapse prevention. It is concluded that the use of SM570 steel saves 140 tons steel in total, approximately 3%. That also reduces the seismic drift demands of the building, greatly decreasing the failure probability against earthquake collapse.