上海因城市轨道交通开通较早而成为国内既有线改造领域的先行者，其既有线改造经历以及经验教训对国内其他城市有一定参考价值。为此，首先回顾上海城市轨道交通既有线改造历程，主要呈现关注重点逐渐从个体向全局过渡、改造内容逐渐多元化和系统化、契合城市与网络发展目标的改造需求持续深化和拓展的发展趋势。其次，总结上海城市轨道交通开展既有线改造工作的要点，改造前以系统思维制定改造计划、改造中以保障施工安全和质量为前提尽量减少对乘客的影响、改造后积极开展后评估。然后从资金支持有限、内外沟通协调效率要求高、项目管理难度大、技术积累不足等方面剖析上海城市轨道交通开展既有线改造工作的难点。最后，展望上海城市轨道交通未来的既有线改造重点工作：探寻更多的既有线改造资金渠道、开展既有线改造项目施工计划与管理机制的改进与创新研究、深化既有线网评估工作、攻关未预留条件的地下车站不停运改扩建技术。

With the early opening of urban rail transit, Shanghai has been a forerunner in urban rail transit operating-line renovationin China. The experiences and lessons learned from Shanghai in operating-line renovations have reference value for other citiesin China. First, the operating-line renovation process of the Shanghai urban rail transit was reviewed. Three main developmenttrends indicate that the focus is on a gradual transition from individual conditions to overall conditions, that the renovationcontents are gradually being diversified and systematized, and that the renovation demands that align with the developmentgoals of the city and urban rail transit network are continuously deepening and expanding. Second, developing a renovation planwith systematic thinking, minimizing the impact on passengers while ensuring construction safety and quality during renovation,and active post-evaluation after renovation are summarized as the key points in the operating-line renovation of Shanghaiurban rail transit. The difficulties in operating-line renovation of Shanghai urban rail transit were analyzed in terms of limitedfinancial support, high-efficiency requirements for internal and external communication, challenges in project management, andinsufficient technology. Important future works for operating-line renovations of Shanghai urban rail transit are discussed,including additional financing channels, research on improvement and innovation of construction plans and management

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