Study On Comparison And Selection Of Deep Sea Discharge Pipeline Construction Schemes

Deep sea discharge pipeline project has the characteristics of regionalism,policy,monopoly of construction techniques,seasonal limitation,and surrounding influences.The number of deep sea discharge pipeline projects built in China is relatively small.Accordingly,studies regarding on the comparison and selection of construction schemes is limited as well,and no universal assessment framework has been formed.Therefore,based on the real case in Tianjin Nangang Industrial Zone,the thesis proposed a scheme comparison framework of deep sea discharge pipeline project to explore the alternative methods for such construction projects.Through reviewing and summarizing the current research of domestic and foreign decision-making theory,according to the characteristics of deep sea discharge pipeline project,two suitable models of scheme comparison and selection were proposed.The first model was based on the value engineering theory combined with the fuzzy analytic hierarchy process.First,the weights of the functional indicators were determined by the fuzzy analytic hierarchy process.Then,the functional coefficients were calculated by the entropy weight technique.Finally,the optimal scheme was determined by calculating the value coefficients.The second model was to use a consistency IOWA(C-IOWA)operator to compare different schemes by constructing the fuzzy preference matrix.The optimal scheme was selected by using the C-IOWA operator to determine the induced components and the recombination weights.According to the surrounding waters condition of Nangang Industrial Zone,a specific scheme comparison index system was established based on the real situation.The thesis validates the scientificity and rationality of the selection model by comparing the real construction plans of the new deep sea discharge pipeline project in Nangang Industrial Zone,Tianjin.By analyzing the differences between the two methods,the applicability and limitations of the methods are proposed.The results showed that the two methods are suitable for general deep sea discharge pipeline construction projects,and the construction cost and the ecological environment influence are the key factors influencing the comparison result of the scheme.Under the policy conditions,the value engineering theory combined with the fuzzy analytic hierarchy process can be selected as the method of scheme comparison,in order to maximize the economic benefits.Otherwise,the C-IOWA operator method shall be applied as the comparison method,considering the surrounding environment of the project.The study provides reference for the government and the investors during their selection of proper construction plans,as well as scheme comparison for other new deep sea discharge pipeline projects.