Abstract: Seismic fortification is important for buildings and civil engineering structures. The shortcomings exposed in present urban fortification ideas and methods call for the criteria optimization. Based on seismic hazard analysis, structural vulnerability analysis, earthquake loss estimation and earthquake casualty rate, this paper presents an optimization method for urban seismic fortification criteria. To quantify the destructiveness, we first introduce the vulnerability index. Initial cost, economic input increment and earthquake loss are discussed on the impact of the fortification intensity. We obtain the optimal economic fortification intensity in the model when the sum of initial cost increment and ecnomic loss is minimum. Considering both the economic input and the casualties, we then find the final optimal fortification intensity which can not only brings about the minimum economic input but also ensures the casualties socially acceptable. Thus, we are able to control the cost and casualties by adjusting the seismic fortification intensity.

Key words: Seismic fortification criteria, Optimization method, Structural vulnerability analysis