Carbon Emissions Calculation Model and Energy Consumption Sensitivity Analysis for the Materialization Stage of Large-Span Stayed-Cable Bridges

To support the achievement of dual-carbon goals in cable-stayed bridge construction, this study establishes quantitative carbon-emission models for each materialization phase using the carbon-emission factor method. A collinearity-corrected carbon accounting approach is then developed by integrating LASSO regression to quantify emissions during the materialization stage systematically. The proposed methodology is validated through a case study of bridge-culvert engineering in a cable-stayed bridge project. The materialization-phase emissions are categorized by production, transportation, and mixing processes of raw materials. Applied to the Dongkou Yangtze River Bridge in Wuhan’s Fourth Ring Road, the model analyzes: 1) material consumption (steel: 31.75×10 4 t, cement: 30.18×10 4 t); 2) on-site/off-site machinery operation (excavators: 95,238t CO 2 -eq); and 3) emission intensity by construction division. Key findings include total materialization-phase emissions: 915,833t (direct:87,183t, indirect: 828,649t). Bridge-culvert works dominate emissions (direct: 83.4%, indirect: 95.5%). Sensitivity analysis identifies low-carbon steel (β=0.38), cement (β=0.18), and diesel (β=0.21) as critical mitigation levers. This study demonstrates that the data quality of key materials (steel, cement) and energy (diesel) significantly affect accounting accuracy (±2.8% uncertainty).