Calculation Methods to Optimize the Number of Pedestals and Evaluate Production Plans for Precast Yards Fabricating Prestressed Bridge Beams and Precast Segments for Poststressed Segmental Erection | Journal of Construction Engineering and Management | Vol 149, No 1

AbstractCurrently, the published methods used to optimize the number of beam pedestals in a precasting yard for bridge beams or segments do not consider all relevant constraints. Therefore, an optimal calculation method based on multiobjective constraints is proposed. The constraints used are the demand plan for erecting beams, the minimum beam storage time, and the actual beam storage time. Two cases were considered based on the relationship between the minimum and actual storage times. When the minimum storage time of the finished beams was equal to the actual storage time, the minimum number of pedestals could be determined through the stage of maximum demand. When the actual storage time of the finished beams exceeded the minimum storage time, multiobjective constraint equations for the production and demand plans of each stage were established, and a logic algorithm is proposed to calculate the minimum number of pedestals. In addition, to identify the appropriate production plan, an optimization method is proposed based on three evaluation indexes: vacancy rate, dispersion, and core area. Taking one project as an example, the minimum number of platforms and optimized production plans were obtained using the proposed method. A complete set of planning processes, including calculation analysis and scheme comparison, is presented in this paper. The results demonstrate that the proposed methods are applicable and can provide a theoretical reference for the optimization of precast yards for bridge construction projects.

Source link