Cost Benefit Analysis Of The Structures Designed For Alternative Seismic Hazard Levels

Abstract

In this study, multiple performance objectives under the various earthquake hazard levels are investigated. In case of well defined earthquake hazard, as an alternative of classical earthquake resistant design principles, it is possible to design structures at different performances depending on structure's initial cost and economic life. In this study, costs of the structure with different performance levels are discussed.Current study is carried out on the reinforced concrete structures that are designed and analyzed for various seismic hazard levels. The aim is to determine, if the risk is released, whether the economic losses can be acceptable or not. In the study, cost of reinforced concrete ductile frames and dual systems that are designed for various seismic performances, are also compared for the economical aspects.To that end, in the first step 3, 5 and 8 storey frames and dual systems of several structures at Life Safety and Immediate Occupancy performance levels was designed for the earthquake hazards of 2% and 10% probability of exceedance in 50 years. The study reveals that if both direct and indirect effects of earthquake such as retrofitting costs, cost of temporary moving, temporary accommodation costs, cost of demolition and reconstructing the building, cost of damage to household goods and business disruption, social disturbance, are be taken into consideration, initial design performance level can be accepted as Immediate Occupancy performance level rather than Life Safety performance which is proposed current earthquake codes. The cost due to injuries and cost due to loss of lives are not included.