In the civil engineering field several typologies of structures – as towers, tall buildings, bridge decks and suspended cables – can be idealized as prismatic bluff bodies as far as their aerodynamic behaviour is concerned. In most of these cases, the wind actions are absolutely the dominant ones, and influence major design choices, determining the structural organism, as well as the exterior shape. The aerodynamic studies on civil-engineering structures are mainly carried out in special wind tunnels where the Atmospheric Boundary Layer (ABL) is reproduced by means of passive devices located along a fetch upstream the body to be tested. In this context, the aerodynamic actions relevant to the design include the mean aerodynamic force and pressure coefficients, as well as the probabilistic characterization of their random fluctuations, generally expressed in terms of Standard Deviation (SD) and Power Spectral Density (PSD) function. Besides, the design of local details, such as cladding elements, requires the probabilistic representation of the local pressure field, which in the separated regions of the boundary layer has strongly non-Gaussian probability distribution and its characterization requires the estimation of high order statistical quantities. The numerical simulation of the flow past a large bluff body and the characterization of the mentioned aerodynamic actions is particularly complicate and is still at the frontier of application in wind engineering. Such difficulties are mainly determined by: (1) the very-high Reynolds number characterizing typical civil engineering problems, which requires a very refined mesh to model correctly the fluid-dynamic field in the neighbourhood of the investigated body; (2) the necessity of modelling unsteady flows, which produce an essential part of the aerodynamic actions on the structure, requires the use of computationally-expensive numerical schemas as Large-Eddy Simulation (LES); (3) the low-frequency dynamical response of typical civil-engineering structures requires very long simulation runs to evaluate statistically-significant loads; (4) the flow incoming on the body must be characterized by a velocity profile and a turbulence PSD compatible with the nature of the atmospheric boundary layer (ABL).