关键词: 运营地铁, 改扩建, 实施方案, 风险分析, 防护措施, 效益评价

Abstract: In order to solve the problems such as inharmonious internal and external environment and backward facilities, rehabilitation and expansion should be carried out for operating metros. Several rehabilitation and expansion schemes related to civil work (including station main body, station entrance/ exit, station ventilation pavilion and small ancillary structures of the station) for Xi′ an metro stations are taken for examples to analyze and summarize the background, implementation, effect, risk sources, technical measures, operating measures, management mechanism, investment and comprehensive benefit of rehabilitation and expansion works. The conclusions are drawn as follows: (1) The schemes for rehabilitation and expansion of metro are various, hence, comparison and selection should be carried out. (2) Sufficient demonstration and checking before scheme implementation should be adopted to minimize the adverse impact, implement risk and project investment. (3) The operational management should be strengthened, and the specific emergency schemes should be made to avoid accidents when constructing in crowded public area. (4) It is short of specification and standard for construction and design of rehabilitation and expansion, as well as the systematic management procedure and mechanism. It is suggested that the optimum construction program and rational management mechanism should be determined as soon as possible.

Key words: operating metro station, rehabilitation and expansion; implementation scheme, risk analysis, protection measures, benefit evaluation