Automated generation of horizontal precast slab stacking plans

Prefabrication is a promising construction method that helps to improve overall productivity, reduce the environmental impact, and improve on-site safety and security. To accelerate the use of prefabrication, we investigate the problem of stacking precast slabs, one of the most common prefabricated components, through mathematical programming methodology. A mixed-integer nonlinear programming model is proposed that incorporates many practical factors, including stack stability, reshuffling work, and dunnage positions. The model aims to minimize the reshuffling of slabs and reduce the area occupied by stacks, which are two crucial objectives considered during slab stacking and transportation. Through extensive experiments, the proposed method is proven to average a 16.56% improvement in optimality compared with the commonly used heuristic stacking method and is thus considered an effective tool for generating stacking plans.