Research On Carbon Emission Calculation And Multi Scenario Simulation Prediction For The Life Cycle Assessment Of Urban Road Engineering

China is currently the world’s largest emitter of greenhouse gases,accounting for about a quarter of the total global greenhouse gas emissions.The "dual carbon" goal is an inevitable choice and urgent need for China to achieve high-quality development.The transportation industry is one of the main sources of global carbon emissions.In recent years,China’s road traffic carbon emissions have continued to grow,accounting for about three-quarters of the total carbon emissions in the transportation sector.As an important component of road transportation,urban road engineering accounts for 5%-25% of transportation carbon emissions during its construction process.Exploring the carbon emissions of urban road engineering and formulating emission reduction strategies is of great practical significance.This thesis is based on the Life Cycle Analysis(LCA)theory to clarify the connotation of carbon emissions from urban road engineering.By analyzing the composition of carbon emissions sources and their correlations in the design,construction,operation,and maintenance stages of road engineering,the characteristics of carbon emissions are summarized.Based on the characteristics of carbon emissions,the range of carbon emissions calculation is determined to include the energy and fuel consumed by materials,mechanical equipment,vehicles,chemical reactions,and carbon emissions during the operation and use of road facilities in various stages of urban road engineering.Analyze the influencing factors of carbon emissions in each stage,and use the comprehensive weighting method to quantify the influencing factors,compare the analysis results,and determine the key influencing factors.Based on the emission coefficient method,a "stage part whole" urban road engineering carbon emission calculation model is constructed from bottom to top,enabling each stage of road engineering to be quantified independently and form a unified entity,intuitively displaying the composition of road engineering carbon emissions and the connections between each stage.Based on this,a carbon emission prediction model for urban road engineering is established by combining the calculation principle and structure of the LEAP model.Green material simulation scenarios and clean energy simulation scenarios are set according to key influencing factors.Taking a certain urban expressway as an example,the construction and operation data of the expressway in 2016 are used as the baseline scenario data to predict the energy consumption and carbon emissions generated by the expressway construction and operation period until 2030 under both scenarios,Comparing the emission reduction potential of two scenarios,the results indicate that material production is the key to energy consumption and carbon emissions during the road construction phase.In 2030,the expressway will reduce emissions by 17.34%compared to the baseline scenario under the green material scenario,and by 16.61%compared to the baseline scenario under the clean energy scenario.Finally,emission reduction suggestions for each stage will be proposed.