Juncheng Zhu

As the global urbanization process continues to accelerate the implementation of the “dual carbon” strategy, urban underground pipelines, as important infrastructure and urban lifelines, have generated significant resource consumption and ecological environmental impacts throughout their entire life cycle. This paper is based on lifecycle assessment (LCA) theoretical framework and systematically defines the scope of lifecycle assessment for underground pipeline projects, covering the stages of raw material production and processing, raw material transportation, construction, operation and maintenance, and disposal. Then, a comprehensive lifecycle inventory database has been established through inventory analysis. A lifecycle environmental impact assessment model for underground pipeline projects has been developed utilizing categorization, characterization, standardization, and weight determination, enabling quantitative evaluation of environmental impacts at each stage. At last, an urban underground pipeline project was selected as a case and the emission inventory data were integrated with the environmental impact assessment model to conduct a systematic analysis across all the lifecycle stages. The results indicate that the photochemical ozone creation potential (POCP), atmospheric particulate matters potential (APMP), and solid waste potential (SWP) have the most significant environmental impacts, and the total environmental impact values are 70, 104 and 83.9 capita equivalent, respectively. Moreover, the raw material production and processing, operation and maintenance, and construction stages are identified as the primary contributors to these environmental impacts, and the values are 17.5, 10.6 and 1.8 capita equivalent, respectively. Based on these findings, targeted improvement measures have been proposed for each stage, providing valuable references for optimizing engineering practices.