地铁建设环境影响评估及减排效益研究:以深圳市为例

地铁大规模建设和运营消耗了大量资源能源,已逐渐成为城市交通环境影响的主要贡献源。基于生命周期评价(life cycle assessment,LCA)方法,以深圳市为研究区域,定量分析了地铁建设过程的资源与能源消耗强度,选取全球变暖潜能值(global warming potential,GWP)为度量指标,构建了地铁建设碳排放分析框架及测算方法,并基于情景分析法预估了减排潜力。结果表明:截至2020年底,深圳已开通运营的地铁线站建设造成的碳排放量约累积达到2730万t CO₂e,其中地铁车站建设碳排放量占比约为72%,地铁隧道建设碳排放量占比约为28%。建设阶段单位里程盾构隧道碳排放强度约为1.3万t CO₂e/km,单位面积车站碳排放强度约为371 t CO₂e/100 m2。通过推广绿色建造技术,如采用再生混凝土和再生钢材,地铁建设阶段最高碳减排率可达到8.5%/a,2021—2035年累积节碳可达到508万tCO₂e,可一定程度上能缓解地铁建设的碳排放压力。

RESEARCH ON ENVIRONMENTAL IMPACT ASSESSMENT AND EMISSION REDUCTION POTENTIAL OF METRO CONSTRUCTION: A CASE STUDY IN SHENZHEN,CHINA

The large-scale construction activities and operation of urban metro consumes huge quantity of resources and energy, which has gradually become a major contribution to the environmental impact of the urban transportation sector. Taking Shenzhen as a case, this paper evaluated the resource and energy consumption intensities of metros' construction stage by using life cycle assessment(LCA) method. The global warming potential(GWP), measured by CO₂ equivalent, was chosen as the impact indicator to build a carbon emission calculation model of metro's construction phase. Meanwhile, scenarios-based analysis was adopted to predict the emission reduction potentials. The results showed that the cumulative carbon emission caused by the construction of metro lines and stations in Shenzhen city reached approximately 27.3 million tons of CO₂e by 2020, of which 72% from the stations' construction, and 28% from the tunnels construction. Specifically, the carbon emission intensities of shield tunnels and stations were approximately 13000 tons CO₂ e/km and 371.2 tons CO₂ e/100 m2, respectively. In addition, the carbon emission reduction rate of metros' construction reached 8.5% annually, or an accumulative amount of 5.08 million tons from 2021 to 2035, if green technologies adopted, such as the use of recycled concrete and recycled steel. And that can probably significantly alleviate the carbon emission of metros' construction.