Abstract: In water transmission and transfer project,the selection of pipe is a technical difficulty for technical personnel as it is of fuzzy incompatibility and multi-objective.In this paper,a fuzzy matter-element evaluation method based on variation coefficient and analytic hierarchy process(AHP)is established.Indexes affecting the selection of pipe materials are analyzed,and a comprehensive evaluation index system for the selection of pipe materials is constructed.Variation coefficient is introduced to modify the subjectivity of AHP in determining the index weights.In such manner,the combination weight of the evaluation indexes are determined,and a fuzzy matter-element evaluation model is established.Furthermore,the optimal pipe type can be determined by using the Euclid's nearness degree together with the principle of value engineering.The model is applied to the pipe selection of a water diversion project in Xinjiang.Calculation result reveals that Fiber-Glass-Reinforced Plastic Matrix Pipe(FRPM)is the most suitable pipe type for the project.The results demonstrate that the optimal pipe type can be determined using the present method according to field engineering conditions and technical characteristics of pipes in consideration of technical,economic,construction,safety and other factors.

Key words: water delivery pipeline, pipe selection, fuzzy matter-element, combination weight, coefficient of variation