Wind Loading Combination considering Response Correlations between Acrosswind and Torsional Directions

풍직각방향과 비틀림방향의 응답상관을 고려한 풍하중 조합

The wind tunnel test was conducted to investigate characteristics of fluctuating wind forces acting on tall buildings for various side ratios (D/B=1.0, 1.1, 1.2, 1.3, 2.0 and 3.0) and different terrain roughnesses. Further, the wind load combination was examined by the correlation of the displacement response between acrosswind and torsional directions through Spectral Modal Analysis Method and Time History Analysis Method. As a result, there was no significant effect of the changing of terrain roughnesses on fluctuating moment coefficients for acrosswind and torsional directions, but they were varied with the changing of wind directions. Acrosswind overturning moment coefficients were highly correlated with the torsional moment coefficient with the increase in wind directions. The response and correlation obtained by Time History Analysis were good agreement with those of Spectral Modal Analysis. Also, the response correlation between acrosswind and torsional directions was highly affected by natural frequency ratios. Hence, the wind load combination for acrosswind and torsional directions shall be considered that when the natural frequencies between acrosswind and torsional directions are close to each other.