Evolution of the crane selection and on-site utilization process for modular construction multilifts

• Crane load capacity check and crane placement location method selection criteria
• Crane counterweight and crane boom clearance algorithm development
• Crane boom clearance to slope surface equation development analysis
• Case study introduction and proposed methodology implementation
• Real project proposed methodology validation and final paper conclusion

Modular construction technology has been used in building construction for decades, having been widely utilized on sites with high traffic volume, restricted accessibility/storage, or business operations which cannot be interrupted by long construction time. A key challenge in this method of construction lies in planning and executing lifts within a short timeframe. In this regard, proper crane selection and site layout optimization can significantly increase productivity and shorten the lifting schedule. This paper thus proposes a methodology for the crane selection process and introduces mathematical algorithms to assess the construction of multi-lift operations. The modular lift process is divided into three stages: crane load and capacity check, crane location, and boom and superlift clearance. Each stage's parameters are introduced, analyzed, and graphically explained. The methodology logic is supported by a generalized mathematical algorithm and is applied and tested on a case study involving the construction of five three-storey dormitories in 10 working days for Muhlenberg College in Allentown, Pennsylvania.