Soil-structure-damper interaction under wind loading

Theoretical investigation is presented for the wind-induced motion of tall/slender structures equipped with tuned mass dampers, taking into account the effect of soil compliancy under the footing. The superstructure is modelled as a lumped mass multi-degree-of-freedom cantilevered system and the soil behaviour, including footing embedment effect, is characterised by a known frequency-dependent compliant matrix. The along-wind turbulence and the cross-wind wake excitation are modelled as stochastic processes which are stationary in time and non-homogeneous in space. A transfer matrix formulation is used to analyse the soil-structure-mass damper interaction in the frequency domain and a Monte-Carlo simulation is employed to demonstrate the system response behaviour in the time domain. Numerical examples show that soil compliancy will affect structural responses and the effectiveness of tuned mass dampers, depending on the properties of the soil, the properties of the structure, the nature of the excitation and the type of the structural response.