Multiple Heavy Lifts Optimization

Abstract

Heavy lift planning has a major impact on construction sequencing, scheduling, budgeting, and safety. This paper addresses problems presented by planning for multiple lifts on a single jobsite. This is a common and particularly challenging planning situation because of the complex trade-offs involved. Conventional intuitive planning procedures lead to suboptimal plans or plans ranked with little quantitative or objective measure. This paper first introduces various factors affecting planning decisions for multiple heavy lifts and then presents an interactive computer-aided process to optimize initial crane configurations and placement locations for multiple lift problems. In the computer-aided planning process, the minimal number of equipment relocations is determined based on an integer programming model, and the precise equipment locations are optimized with an interactive procedure using objective performance functions. Objectives involve cost, safety, and area interference (area sterilization). These optimization procedures are implemented in the critical operations planning environment (COPE). A case study is used to demonstrate the optimization process. It is concluded, based on a case study and external reviews, that the process and algorithms presented help produce good plans for multiple heavy lifts on construction sites.