Carbon emission reduction scheme of railway subgrade retaining wall and carbon reduction strategies
The carbon emission generated by railroad retaining wall in the whole life cycle of railroad foundation cannot be ignored.To explore the carbon emission level of different types of retaining walls,three typical retaining walls were selected to carry out the research,extracted the optimal scheme of carbon emission reduction and analyzed the impacts of different combinations of strategies on carbon emission,and then put forward a comprehensive strategy of carbon emission reduction.Firstly,based on the LCA theory,the carbon emission of the whole life cycle of reinforced soil retaining wall,gravity retaining wall and soil nail wall were divided into four phases.There were the production of building materials,transportation of building materials,construction and operation and maintenance.Based on the functional unit,the carbon emission factor method was utilized to calculate the carbon emission of each type of retaining wall in each phase and the total carbon emission according to the carbon emission calculation model.The results show that the reinforced earth retaining wall has a carbon sequestration effect throughout its life cycle due to the carbon sequestration capacity of slope vegetation,and the amount of carbon sequestration is 197.300 t.The total carbon emissions of gravity retaining wall and soil nail wall are 489.344 t and 51.834 t,respectively,so that the reinforced earth retaining wall is the optimal solution for carbon emission reduction.Then the reinforced earth retaining wall is taken as the research object to extract the carbon emission influencing factors in its design stage.The most sensitive factor of its carbon emission is identified as the slope vegetation type,followed by the slope of retaining wall by using sensitivity analysis method.Finally,three vegetation types of bermudagrass,knotweed and ryegrass with four slopes of 1∶0.4,1∶0.5,1∶0.6 and 1∶0.7 are selected to analyze the comprehensive effects of different strategy combinations on the carbon emissions of reinforced earth retaining walls in the whole life cycle.The study shows that for bermudagrass,which has a strong carbon sink capacity,lowering the slope can improve the whole life cycle carbon sequestration;for knotweed,which has a general carbon sink capacity,avoiding unfavorable slopes can improve the whole life cycle carbon sequestration.For ryegrass,which has a weaker carbon sink capacity,upgrading the slope can improve the whole life cycle carbon sequestration of the retaining wall.The research results can provide a theoretical basis for the carbon reduction design of railroad retaining walls.
万方数据
维普
