Study On The Planning Theory Of Underground Transport System Connection

Urban transport is an important part of urban systems, and it has played an irreplaceable role in the development of the city. However, as China's rapid economic development and promotion of urbanization, urban traffic worsening a serious impact on people's work and life, especially urban transport construction land shortage has become an important factor restricting urban development. Through the rapid expansion of the road surface area to solve urban traffic congestion has become very real. Taking use of underground space resources to construct underground transportation has become one important way to solve the problem of urban traffic congestion.Development of underground transportation can effectively alleviate the current problems existing with ground transportation, and it will also provide an effective means of three-dimensional development of the city. Many cities have been building successful examples of underground transportation system, especially the success stories of underground expressway, but it is lack of systematic theory and method research on connection between underground expressway and ground transportation. Underground expressway have some differences from ground transportation systems and rail transit systems in the operating environment, service targets, functions and features, so taking use of existing theoretical approaches to plan underground transportation system is not enough .On the basis of urban planning theory, operations research, and theories of traffic flow, this paper focuses on the layout of urban underground expressway network. In the comparison of the current method of urban expressway network layout, the method of point,line and area analysis is tried to put forward, and the principles of the layout of expressway network is given. Then the author analyzes the location problems involving distance decay, share rate, and depot efficiency on the passageways of urban underground expressway. The depot choice model was built with the object of maximum depot efficiency, and then an example was presented to illustrate the feasibility of the model. The underground expressway can bring more benefits, although it costs a lot. The indirect benefit costs are difficult to be determined in national economy evaluation model of underground projects, This paper mainly introduces the recognition method of project cost and benefit from the economic perspective and gives a quantitative model of related economic benefit to determine underground expressway project feasibility . Finally, the development of the principles of underground expressway has been studied.The study in this paper not only proposes a new direction for urban underground transport system, the research results will also provide the basis of planning, construction and management of underground expressway system theoretically.