Theory And Application Of Generalized Life Cycle Cost Of Urban Rail Transit Project

A dynamic model of generalized life cycle cost of urban rail transit was established based on life cycle cost theory in order to facilitate the selection and decision-making of urban rail transit system in big cities. During the development of the model, the urban rail transit system was considered as a quasi-public product and time value of capital was taken into account. In order to establish the model, components of the life cycle cost were studied firstly in terms of the internal and external cost, mathematical models of which were developed individually as well. Then, a theoretical frame of generalized life cycle cost of urban rail transit was presented. Result of the study could serve as reference for the selection and decision-making of urban rail transit system in big cities.Components of life cycle cost were studied stage by stage during the life cycle of urban rail system. It should be noted that when generalized life cycle cost was considered, time value of capital must be taken into account. The study indicated that generalized life cycle cost was made up of external cost and internal cost, such as the yearly decision design cost, construction cost, operation maintenance cost, salvage, and each item of external cost. Accordingly, structure of each cost was studied in detail. In addition, process and suitable time for the analysis of generalized life cycle cost were discussed as well as the advantage of this method.Surveys on urban rail transit systems under operating in big cities in China were conducted, such as Beijing, Shanghai, Tianjin, Guangzhou, Shenzhen, Nanjing, etc. The survey focused on the components and influencing factors of internal cost, including civil engineering cost, electromechanical cost, operation maintenance cost. Data for urban rail transit lines laid both ground and underground were collected. According to the result of the survey, model of internal cost for each period—decision design stage, construction stage, operation maintenance stage, and recycle stage in the end of the service life—was developed. Concept of blocking cost and its mathematical model, followed by the discussion of its calculation steps, were come up with during the development of the external cost model. At the same time, the external cost was also studied. Some mathematical models of multiple benefits and cost due to the building of urban rail transit system were established, which include economic growth benefit, alternative public transit on the ground benefit, energy saving benefit, environmental cost, real estate betterment benefit along the line, productivity enhance benefit, travel time saving benefit, safety improving benefit and noise cost. Two methods of cost estimation with incomplete information were introduced:small sample fuzzy clustering model and small sample support vector machine model.Optimization of generalized life cycle cost model was made through introducing objective function and constraint conditions. Before optimization, the optimizing objective and content were addressed firstly.A case study of Shijiazhuang urban rail transit Line 1 was made. Two laying modes of the route were assumed—ground line and underground line. Both the traditional life cycle cost and the generalized life cycle cost of each mode were calculated. Results indicated that the traditional life cycle cost is 0.2175 billion Yuan per km for ground line, and it is 0.5227 billion Yuan per km for underground line; the generalized life cycle cost is 0.5227 billion Yuan per km for underground line, and it is 0.5533 billion Yuan per km for ground line. Therefore, Line 1 should be selected ground according to the traditional life cycle cost, while the underground line should be choosed according to the generalized life cycle cost, considering their lower cost. The results also explained why more urban rail transit systems have been constructed underground in big cities in China in recent years.