Study On The Rapid Assessment Method Of Earthquake-caused Direct Economic Loss

As a typical natural disaster with lower occurrence and huger damage, earthquake often causes inestimable losses. Located between Circum-Pacific seismic belt and Eurasia seismic belt, China suffers from quite frequent seismic activities. And with the rapid economic development and gradually intensive personnel, there is a growing seismic threat for our country. Therefore, a systematic research on the rapid evaluation method of earthquake-caused direct economic loss takes on an important theoretic meaning and realistic values.Based on the analysis results of earthquake-caused economic loss, this paper employs the fragility analysis, classifies buildings according to structure type and occupancy class, models the direct economic loss from three aspects and mainly researches the unit replacement cost and the structural loss ratio. With the use of SPSS, a unitary linear recursive analysis of the relation between unit replacement cost and year is performed and regression equations which are with higher goodness of fit and approved by significant test are obtained. Through qualitative analysis of hazard factors and characteristics of hazard-affected bodies, earthquake magnitude, focal depth, seismic fortification intensity, basic design acceleration of ground motion, unit replacement cost and GDP are chosen as input variables, while structural loss ratios under the different damage states are output variables. A back propagation neural network(BPNN) is built and the Levenberg-Marquardt(LM) algorithm is used to train the network. Meanwhile, the generalization ability is improved by the early termination algorithm. The training results meet the requirements of speed and accuracy. Through systematic summary of authoritative research, this paper also provides convincing reference to the evaluation of decoration loss and building contents loss.The preliminary results can offer an effective method for the rapid evaluation of the earthquake-caused direct economic loss and provide basis for contingency plans and hazard reduction measures.