Research on Reserved Engineering Design in Urban Rail Transit

Objective In the early stages of projects, planned reservation of civil works, electromechanical systems, and interface access conditions for urban rail transit line subsequent construction has become a new norm in urban rail transit engineering. This approach can effectively reduce construction difficulties, risks and investment costs in subsequent projects. Therefore, based on current practices in reservation engineering, it is necessary to summarize the issues encountered during the design phase of reservation engineering involved in urban rail transit projects（hereinafter referred to as ′reserved projects′）. Method Reserved projects are categorized into 4 types, with an analysis of the characteristics and main subcategories of each type. The impact of urban development, upper-level planning, project implementation conditions, and project investment/construction sequencing 4 key factors on reserved projects is analyzed. Taking the line network construction of Chongqing Rail Transit as the research background, three typical cases of reserved projects are selected, and the construction experience of these three cases are summarized, and optimization suggestions are put forward. Result ＆ Conclusion Reserved projects should be aligned with urban rail transit line network planning and coordinated with urban development to reasonably determine the functions of reserved projects. Reserved projects in transport hub projects should adopt inclusive design principles and integrate with the overall design of the hub area. Municipal reserved projects should maintain the authority and stability of planning schemes to reduce investment in reserved projects.