Effects of Crane - Building Relative Position and Exposure Height on Wind Loading of Tower Cranes

This study investigates wind loading on tower cranes erected beside or within under-construction buildings using RANS simulations with the SST k−ω model under an Atmospheric Boundary Layer (ABL) inlet profile. A series of parametric CFD analyses were conducted to quantify how wind direction, crane orientation relative to the building edges, building height, exposed mast height above the roofline, the presence or absence of the operator cab and current assembly or disassembly status influence the aerodynamic loading. Multiple wind-attack angles and mast configurations were evaluated to compare drag forces, moment response, and load redistribution caused by the interaction between the building-generated flow field and the crane. Results show that building-induced flow separation at roof corners, upward streamline deflection, and wake expansion significantly modify the local velocity field incident on the crane. These effects are the strongest when only part of the mast extends above the roof, producing substantial changes in section-wise drag, while the operator cab introduces additional blockage at oblique winds. To generalize these findings, each configuration was decomposed into three projected-area categories - first-contact, second-contact, and shielded surfaces - computed for any crane orientation and exposed height using a MATLAB-based tool. The CFD database was then used to construct an empirical relation expressing drag as a function of directional areas, mast exposure, and cab presence. The overturning moment was evaluated as the product of the drag force and the height of the center of pressure. This framework provides an efficient method for estimating wind loads on cranes positioned on buildings, supporting safety evaluation during high-rise construction.