Calibration Capability Of The Urban Seismic Prevention And Disaster Mitigation & Research On Acceptable Risk Level

The cities'disaster reduction is the important component of the national public security. It is important for the people's personal safety and property and society's sustainable development. In 2004, China government put forward that the cities with dense population or developed economy and the area off the seashore should have ability to resist earthquake(M=6) before 2020. It is really a challenge for researchers to evaluate the cities'ability reducing earthquake disaster. It will provide an objective criterion for evaluating and comparing city's ability reducing earthquake disasters among various cities, and it will also give advices to decision on reducing earthquake disaster.Based on the current research achievements on reducing earthquake disaster, and used the theory of the economics, operations research and other disciplines related to it, this paper is setting up an index system about evaluating cities'ability reducing earthquake disasters. It carries out research from the following several aspects:1. Set up the the index system on city's ability reducing earthquake disastersThe conception of cities'ability reducing earthquake is presented, the ability could be evaluated with three basic elements– the seismic casualty and economic loss during the certain earthquake and the recovery time after the certain earthquake. Based on these three elements, six factors affecting cities'ability reducing earthquake disasters are proposed–seismic hazard analysis, earthquake monitor and prediction, the capacity on building resisting earthquake damage, the influence of the urban political, economic, social and cultural factors, ability on cities'disaster management, and ability on earthquake hazard mitigation and rescue. In accordance with the specific content of the various indicators and its impact, this paper improves and develops its various subsystems, forming a complete urban earthquake disaster prevention and mitigation capability assessment framework.Collecting and collating all the views of experts in different fields by surveying, and using the improved analytic hierarchy process to determine the weight of the three criteria and six indicators. At the same time, according to the characteristics of different evaluation targets, combined with the theory of the entropy two-base-point and partial correlation analysis, this paper calculates all the weight of the system, and it forms a complete evaluation system for evaluating cites'capacity on reducing earthquake disaster.2,Put forward methods on evaluating the capacity of the various indicators on resistancing earthquake disasterBecause various factors play various role in index system, this paper applies the different methods to evaluate the factors'ability on reducing earthquake disaster.First of all, according the data of the sevel earthquakes damage prediction from"75"and Wenchuan earthquake survey, this paper determines the weight value of four factors (earthquake resistance condition, construction time, structure type and location condition) to impact the capacity of build to anti-seismic damage, while the four factors proposed the method to evaluate the capacity of structures in seismic index.Secondly, it uses two-base-point method to evaluate the urban lifeline system satisfaction, and determines its capacity in urban earthquake disaster prevention and mitigation.At last, the method of dual base-point is proposed to evaluate the satisfaction condition of lifelines'performance after earthquake, consequently to gain the value of lifeline system in index system.3,Proposed the method of computing seismic casualty, economic loss and recovery time(1)According to the results on the earthquake damage prediction of a number of cities from " 95 " Plan, it statistics and regression the relationship between the builds'anti-seismic capacity and the personnel casualty rates. At the same time, considering other factors, it also calculates the relationship between different seismic intensity factors under the anti-seismic capacity and casualties.(2)First, about direct economic loss, the relation between the seismic ability index of structures and structural loss and belongings loss are gained utilizing the cities'prediction results of earthquake disasters which are made during the period of 95. Then, it calculates the earthquake indirect economic losses by considering the ability to anti-seismic structure, socio-economic structure and the other five indicators of seismic capacity. Finally, considering the relevant provisions on Chinese earthquake emergency rescue, it obtains the direct investment on the earthquake disaster relief. Combinating by three parts, the total value of economic losses by the earthquake could be determined.(3)According the ATC-13 report of FEMA, the recovery time of various damage condition are gained statistically. The according to the conception of recovery time this paper defined, the method of computing recovery time is presented.4,research on acceptable risk level for cities'ability in reducing earthquake disastersIt presents the study on the acceptable risk level for city's ability in reducing earthquake disasters. The so-called acceptable risk level refers to the threshold for the safety level based on the risk analysis and assessment. It defines the acceptable risk levels for the corresponding risk-prevention measures, including failure probability and the consequences of measure failure, such as human casualty and economic loss, etc. In more detailed way, the paper has discussed the methods to use ALARP principle and F-N curve to determine the acceptable risk and their applications in the city's ability in reducing earthquake disasters. However, it remains a controversial issue to make accurate assessment of the acceptable risk level in the actual situations, which is still left be solved through the joint efforts of the governmental departments, engineers, scholars and the public concerned.5,suggest the method of computing the comprehensive index on city's seismic ability and some examplesBased on the concept of fuzzy membership function, the urban earthquake disaster prevention and mitigation capability index is calculated by the capacity of the various subsystems in reducing earthquake disasters. And on this basis, it proposes the standard on dividing the ability to resist the different intensity earthquakes.At the same time, Making use of evaluation model mentioned above, ten cities home and abroad is evaluated on their ability reducing earthquake disaster, and then causes about these cities'seismic ability difference are demonstrated.