Low-construction-emissions Optimization for Railway Alignment Fine-grained Designs within Densely Populated Urban Areas

Abstract

Fine adjusting the existing manual railway alignment designs in densely populated urban areas to further reduce construction costs and emissions is a very challenging issue. To address this issue, this paper develops a framework of fine-grained optimization for railway alignment (FORA) to minimize the construction costs and emissions of a given manual railway design. This approach finely optimizes the alignment based on manually selected route, and proposes an improved two-level dynamic programming (DP) algorithm that incorporates the carbon dioxide emissions of buildings and railways into the objective function for calculation. Then, the proposed methodology is applied to fine-tune the alignment of a real-world railway in its preliminary design stage. The results verify that FORA effectively optimizes the railway alignment, decreasing the building demolition area, carbon dioxide emissions, and total construction cost by 7.56%, 3.42% and 3.03%, respectively, compared with the given manual route.