Keywords: Building Control, Wind Loading, Liquid Dampers, Benchmark Studies
The effectiveness of using liquid dampers such as Tuned Liquid Column Dampers in suppressing along wind and cross wind motion of a 76 storey tall building is investigated analytically. The 76 - storey building is the one adopted by the Building Control Group of the International Association for Structural Control as one of benchmark problems for benchmark studies in wind motion control.
The building is 306 meters tall with an approximately square cross section with chamfer on two corners. The building possesses a height to width aspect ratio of 7.3 to 1 making it a slender building and hence ideal for wind control studies. For mathematical modeling purposes, the building will be modeled as a 19 lumped mass dynamic system with both lateral and torsional degrees of freedom considered. A time domain analysis using direct integration of the governing equations of motion will be used for the analyses.
The effect of Liquid Damper parameters such as mass ratio, tuning ratio, orifice opening ratio and others on the performance of the building will be assessed and optimized parameters identified.
The concurrent along wind and cross wind loads will be obtained from wind tunnel studies of a scaled model of the building performed at the Fluids Laboratory of the University of Sydney by measuring and integrating pressures acting on all four faces of the model at various heights. Using actual wind data will allow an accurate assessment of the effectiveness of both the U-shaped and V-shaped Tuned Liquid Column Dampers as viable control devices for tall buildings. One aspect of the study is to determine the optimum location and number of liquid columns which will result in not only the lateral motion control but also the torsional control. The building model adopted will also take into account axial force effects.