Research On Rockfill Dam Construction Time-quality-cost Trade-off Optimization Based On Pareto Solution

With large scale and mechanical equipment of all kinds in engineering construction,rockfill dam construction is a very complicated process and the construction objectives(time,quality and cost)are affected by many factors,which brings a big challenge to construction management.Whether the three core elements(time-quality-cost)can be trade-off optimization or not is an important measure of the project evaluation in dam construction.Between the three goals are both independent and unified,and any one of these factors may have a significant effect on the other two.How to keeping the balance among them based on the concept of Pareto solution has become an important issue facing the engineering decision makers.Aiming at the problem of lack of time-quality-cost research in dam construction field and multi-objective trade-off optimization did not have only one optimal solution but a group of Pareto solution,traditional algorithms(such as genetic algorithm,non-dominated sorting genetic algorithm,etc)has taken it into account in some degree,but the calculation process is complicated,so it is necessary to improve the algorithm based on Pareto solution to improve the efficiency of the algorithm.The paper built rockfill dam construction time-quality-cost trade-off optimization mathematics model,and Pareto superposition model was built to solve the dominance relation between combination solutions whose conclusion showed that the combination solution which was composed by Pareto solutions of process was still Pareto solution.The feasibility of coupling LWS(Linear Weighted Sum)method was verified by comparative analysis of LWS method and TOPSIS method,and the modified NSGA-?coupling LWS was proposed based on the conclusion of Pareto superposition model and integrated with multi-attribute utility function.With practical engineering examples,the improved algorithm was used to solve the problem of time-quality-cost trade-off optimization based on uncertainty analysis,which reduced the computational complexity,improved the computational efficiency and robustness of the algorithm,and overcame the problem that the optimal solution was not only one.Simultaneously,combined with a rockfill dam project,the computational efficiency was improved by applying the modified algorithm,and chose the best compromise solution that accorded with engineering practice.