The Study Of Water Supply Network Leakage Evaluation Based On Improved Analytic Hierarchy Process

For the daily operation or maintenance of water-supply pinelines,water-supply enterprise face the serious financial problems.In addition,water-supply enterprise also face the problems of water-leakage,emergency shutdown,free water supply and the maintenance charge for road excavating,sometimes these charges cost more than the direct cost of pipeline maintenance.With the aging problems of water-supply pinelines become more and more serious,the probability of pipeline accident also increase significantly,in the longrun replacement of the aging pipeline is more economical and effective for water-supply enterprese.Through the analysis of pipeline leakage-influence factors in the pilot area in former shanghai ** waterworks,this article carries out the construction and study of the water-pipeline leakage evaluation system.To begin with,on the data basis of network attribute and repairing record in the pilot area,investigating the effect of various factors on the health of pipeline networks.1 the probability of pipeline accident is inversely proportional to the diameter of pipelines.The larger the pipeline diameter,the smaller the probabilty of pipeline accident;2 the accident probability of each pipeline material from big to small is:concrete,ductile,steel,plastic,cast iron;3 by the increase of pipeline age,the failure probability rises slowly;4 the accident probability of each interfaces from big to small is: socket(asbestos cement),welding,socket(rubber),flange,adhesive,socket(lead);5 the history of pipeline failure has a direct and obvious effect on the future accident probability,more accident is likely to happen in the area where failure has ever took place.Next,by the statistical analysis method based on improved Analytic Hierarchy Process(AHP),carries out the research on the health status evaluation sysytem of the water-supply network in the pilot area.According to the maintenance data in the pilot area,build a fuzzy evaluation matrix and obtain the weight distribution of water-supply network health status evaluation system,which shows as this result: diameter0.2825;material 0.1401;age 0.1371;interface 0.1726;history-failure-rate 0.2676.Choose the evaluation index of the minimum leakage probability as a reference sequence,correlation analysis method is used to evaluate the correlation degree of each evaluation index.Combine the index weight and correlation coefficient to complete the health coefficient of each factor,and build the leakage evaluating system of the water-supply network in the pilot area.Finally,on the data basis of network attribute and repairing record in the controlled area with the calculated health coefficient of each factor,calculate the pipeline health degree and levels in the controlled area,and analyze the difference of health levels in each area.Put forward with the commonly used detection method and the renovation recommendation in the pipeline diagnosis and renovation system,and improve the daily management of the water-supply network.