Lifting demand-based zoning for minimizing worker vertical transportation time in high-rise building construction

With an increase in the number of high-rise building construction projects over the last decade, efficient vertical transportation of resources during construction has become increasingly important. Zoning divides the lifting demand into several vertical clusters of floors and assigns a group of lifts for each cluster. Although zoning has great potential in minimizing the vertical transportation time, it is challenging to derive an optimal zoning configuration for the construction of high-rise buildings because lifting demand can vary significantly with construction progress. To address this challenge, this paper introduces a simulation model that can assist in determining the optimal zoning configuration under varying lifting demand. Application of the model to a high-rise residential building project shows that lifting demand-based zoning can reduce the vertical transportation time by about 40%. Based on this, it is concluded that the model has a great potential to minimize workers' idle time and increase labor productivity. This paper is of relevance to researchers with respect to the development of a mathematical model that can identify the optimal zoning configuration. This paper is also of value to practitioners in terms of providing an effective tool to optimize the vertical transportation plan in the construction of a high-rise building. (C) 2013 Elsevier B.V. All rights reserved.