The Bilevel Programming Model of Earthwork Allocation System

摘要

The earthwork allocation which is common in construction projects and directly affects the quality,costs and scheduling of project is a transportation problem with hierarchical structure.Linear programming model can not clearly reflect the characteristics of the system.Considering Bilevel Programming is the one of useful tools for solving the problem with this structure,in this paper,based on the analysis of time-space relationship of earthwork allocation system,the bilevel programming model is established. The objective of upper level is that of minimizing the transportation costs. And the objective of lower level is that of optimizing the schedules of excavation and embankment activities.In addition,a hybrid particle swarm optimization algorithm is proposed to solve the model by combining the method of particle swarm optimization (PSO) with simplex algorithm. Eventually,an example of the model application to a hydropower project in China is presented. The findings of this application show that the model depicts the hierarchical structure of the earthwork allocation problem better,the algorithm is feasible and allocation plan is effectively improved.