Optimizing Material Hoisting Operations and Storage Cells in Single Multi-storey Tower Block Construction by Genetic Algorithm

Abstract

During construction, materials have to be stored properly and transported within a site area or even different storeys in a high-rise structure. The total costs for storage and transportation are prime concerns. Optimizing material storage locations so as to pay the least transportation costs induced during the project period is a typical construction management problem. In this paper, a genetic algorithm (GA) approach to optimize the vertical hoisting and storage layout for a high-rise multi-storey tower building in confined sites is studied. Costs include the storage and distribution costs which are calculated in terms of vertical transportation, horizontal movements and then vertical distribution expenses. The sum of these costs is set as the objective function for optimization. Since it is a typical multiple-level warehouse layout and distribution problem, which is NP-hard in nature, an effective assignment system with GA approach is applied. An example of 10 types of materials to be stored and distributed in a 30-storey building is used as a numerical example to illustrate the model development. The results also demonstrate the effectiveness of applying the GA in minimizing the total transportation costs that verify the practical application of the proposed approach.