Multi-Objective Optimization of Resource-Constrained Construction Scheduling for Power Transmission and Distribution Projects Considering Prefabricated Components

Research on low-carbon construction in power transmission and distribution (PTD) projects has mainly focused on carbon accounting and emission-reduction assessment, with limited consideration of construction method differences and shared resource constraints. This study proposes a multi-objective optimization method for resource-constrained construction scheduling considering prefabricated components. The project is decomposed into construction units and procedures, and candidate construction methods are defined by carbon emissions, cost, duration, prefabrication rate, and resource demand. The lower level generates representative schemes from procedure-level method combinations, while the upper-level mixed-integer linear programming (MILP) model determines construction-unit schemes, resource input levels, and start times under precedence and shared resource constraints. An ε-constraint method is used to obtain a carbon-prioritized scheme. A 110 kV PTD case study shows that, compared with the cast-in-place baseline, the carbon-prioritized scheme reduces carbon emissions and duration by 17.45% and 14.66%, respectively, while maintaining comparable cost. Compared with the minimum-carbon scheme, it increases carbon emissions by only 0.21%, but shortens duration by 10.00% and slightly reduces cost. The results demonstrate that the proposed method can shorten construction duration and reduce cost while keeping carbon emissions close to the minimum level.