Research on risk factors identification and optimization strategies for railway tunnel construction in ecologically sensitive areas

When constructing railway tunnels in ecologically sensitive areas, numerous risks with high interdependence exist. Current risk identification methods are often unsystematic, prone to significant omissions, and may jeopardize construction safety and the ecological environment. This study uses the Xi'ning - Huangshengguan section of the Xi'ning - Chengdu Railway as a case study to quantitatively identify and hierarchically analyze the key influencing factors of railway tunnel construction risks. Seventeen core influencing factors were first distilled through literature review and expert questionnaires. Then, a DEMATEL-AISM hybrid model was employed to analyze expert rating data from levels 0-4, constructing a five - level adversarial hierarchical structure. The results show that in terms of centrality, environmental awareness (S16), regulatory system (S17), and construction methods (S8) rank the top three with centralities of 9.48, 9.40, and 8.90, indicating their significant system - wide impact. Causality analysis reveals that climate condition (S4) and construction season (S3) are the strongest root causes, while drainage system design (S11) and pollutant handling (S13) are most susceptible to other factors. By controlling four surface - level factors (construction equipment and materials S9, drainage system design S11, spoil dump design S12, and pollutant handling S13), a risk reduction rate of 62% can be achieved. This study offers a clear prioritization of risk factors for railway tunnel construction in ecologically sensitive areas, assisting projects in more effectively reducing risks during planning and construction.