Abstract

Extreme wind speeds pose a serious threat to tower crane stability. Out-of-service wind loads trigger moments that may lead to overturning of a tower crane. Even if the tower crane is anchored to the ground, its structural integrity can be compromised by strong winds since the pressure exerted by the latter can lead to excessive deflections of the mast (which may be a main cause for collapse of the entire structure). Paradoxically, although strong winds have been linked to some catastrophic failures of tower cranes, their effect is often overlooked from a construction management perspective when the models for these cranes are selected during construction planning. Moreover, tower crane location and resources supply locations selection both significantly influence the tower crane model designation and subsequently the overall productivity of the project. This paper proposes a methodology which is consisting of (i) twofold mathematical distance-based-optimization technique encompassing the crane capacity (represented as the lifted moments) and hook operation time to analyze the tower crane site layout combinatorial optimization (determining the optimal crane and the corresponding material supply locations) therefore, facilitating selecting the tower crane model through the lifting critical radius. This optimization gives practitioners the option to explore the effect of different sets of constraints on productivity and overall lifting moments. In this respect, the planning team can choose to favor faster crane operations (i.e., a tighter schedule of crane operations), or they may opt to minimize the lifting-moment, choosing a more conservative crane capacity model to mitigate total cost (ii) a static wind analysis to investigate the efficiency of the tower crane model selected to withstand extreme wind speeds against overturning (through grounding bearing pressures reactions) and mast excessive deformation (compared to allowable deflection constraints). The proposed methodology is applied on a large-scale construction site with 514 crane and material supply location and the selected tower crane model resistance against maximum potential wind speed is examined and ballast base dimensions are determined. Additionally, a case study from the existing literature is investigated as a small-scale construction site and more improved site layout optimization is generated. Finally, a well-known-real-world crane accident is analyzed to validate the performance of the proposed wind static analysis method.