首条地铁的“稳定”与“弹性”

The "Stabilization" and "Flexibility" of the First Metro

研究目的:首条地铁规划建设得如何,对该座城市的轨道交通持续发展影响很大,有的因为规划不尽合理,即使建设规划获批,也迟迟不能开工建设,有的因为建设过程中出现新的变化,原方案难以适应,而影响建设进程。本文以长沙市轨道交通2号线为工程背景,探讨首条地铁线路的起终点、线路走向(经由点)、线网换乘节点、车辆基地和停车场规划建设方案的"稳定"与"弹性"问题,以期为城市轨道交通的规划建设提供借鉴。研究结论:(1)首条地铁的起点或终点在延伸方向存在调整的可能时可以考虑"以退为进"的策略先缩回一个站,延伸工程与本期工程建设期相差较近时可以考虑延伸端车站仅设单渡线折返,起点或终点在不增加太多工程量的情况下要尽量预留延伸条件;(2)稳定首条地铁线位时,也需要考虑为将来网络调整、加密线路预留一定的弹性;(3)线网换乘节点的及早稳定对换乘节点的实施十分重要:是同步建设、预留工程还是预留条件,对换乘站的功能实现影响巨大,首条地铁适当加密站点可以为后续网络调整加密线路时提供换乘条件;(4)首条地铁线路规划建设稳定车辆段方案时,应考虑延伸段建设时序或建设方案的弹性,避免延伸段迟迟不建或一次延伸不到位而造成的不良后果;(5)本研究成果可供当前正在筹划建设地铁的城市参考或借鉴。

Research purposes： How to plan the first metro construction has great effect on the city＇ s rail transit sustainable development. Rail planning of some cities are not reasonable,even if the construction plan has approved,the rail transit also cannot start construction; because of the emergence of new changes in the process of construction for some cities,the original scheme is difficult to adapt to the changes,and impacts the construction process. Taking Changsha rail transit line 2 as the engineering background,this paper discusses the ＂stabilization ＂and ＂flexibility ＂problem about the terminal,the alignment（via station）,the transfer nodes of network,the base for rail transit vehicle and the parking lots in the procedure of planning and construction. The experience can be used as a reference for planning and construction of the urban rail transit.Research conclusions：（1） When the first metro starting point or end point in the direction of extension may be adjusted,the ＂retreat＂strategy which is retracting a station can be considered; when the construction period of the extending project and this project is close,a single crossover in the extending station can be considered; when the quantity of engineering is not increased too much,the extension condition is reserved.（2） The stability of first metro,also needs to consider for future network adjustment and retain the flexibility of adding lines in the rail transit network.（3） It＇s important to stabilize and implement the rail transits transfer node in early period,synchronous construction,engineering or reserved conditions has enormous impact on the realization of the function to the station. Adding some station to the first rail transit can provide transfer conditions for subsequent rail transit adjustment.（4） The construction of the base for rail transit vehicle and the parking lots,should consider construction sequence of the extension or flexibility of construction schemes,to avoid the adverse consequences that the extending project cannot build in time or not in place.（5） The research results can be used as a reference for planning the construction of city＇s rail transit.