Test of a PSHA Map of China with Fortification Benefit Evaluation

AbstractA path for testing a probabilistic seismic hazard assessment (PSHA) map is presented in this paper via the evaluation of fortification benefit with two indices, economic benefit and safety benefit. The effect of fortification intensity on the vulnerability of the engineering structure is emphasized in the damage estimation of the evaluation. The expected losses and casualties are calculated based on the total areas in each of the five damage states with local parameters. The result of a case study of the 1990 PSHA map of China shows that the expected total reduction of loss from the damage to brick concrete and reinforced concrete buildings constructed during the in-service period of the map and damaged in the subsequent destructive earthquakes is RMB 216.5 billion. Thus the expected economic benefit is RMB 17.5 billion in comparison to the additional fortification cost of RMB 199.0 billion. The expected casualty reductions are 20,838 fewer deaths and 77,801 fewer serious injuries. This indicates that the implementation of the 1990 PSHA map has indeed played a beneficial role in earthquake disaster mitigation. The evaluation result of the marginal benefit of fortification, in terms of increasing or decreasing the fortification intensities by one degree further for the whole country, shows that the fortification level adopted in China is appropriate as a whole.