铁路节能环保与安全卫生

在铁路工程碳排放特征分析的基础上，明确涵盖施工人员作业、建筑材料生产运输及施工机械运行的全过程排放核算边界，构建铁路工程建设阶段碳排放计算模型。基于评价结果生成蒙特卡洛模型输入随机变量的概率密度函数，计算出输出正态分布曲线的峰底宽度和变异系数，反映碳排放因子不确定性对碳排放量计算误差的影响。通过实例分析和验证，得出桥梁下部工程施工碳排放量占比最大(64.7%)；柴油机械在使用不同燃料类别的机械中碳排放量占比最高(58.9%)。同时分析了不同工艺生产的钢材的碳排放因子不确定性影响，得到采用EAF工艺生产的钢材对碳排放量计算结果的影响最小。该研究为工程碳排放精准核算提供了方法学支撑与实证参考。

This article clarifies the emission accounting boundaries covering the entire process of construction personnel operations, production and transportation of building materials, and operation of construction machinery. And based on the evaluation results, generate a probability density function for the input random variables in the Monte Carlo model, calculate the peak to bottom width and coefficient of variation of the output normal distribution curve, and reflect the impact of carbon emission factor uncertainty on the calculation error of carbon emissions. Through case analysis and verification, it is found that the carbon emissions from the construction of the lower part of bridges account for the largest proportion(64.7%), and the carbon emissions from diesel machinery account for the highest proportion(58.9%) among machinery using different fuel categories. Additionally, the study analyzes the impact of the uncertainty of carbon emission factors for steel production using different processes and concludes that the use of steel produced by the EAF process has the least impact on the calculated carbon emissions. This study provides methodological support and empirical reference for accurate accounting of engineering carbon emissions.