Experimental study on wind force coefficient of a truss arch tower with multiple skewbacks

Abstract

A truss arch tower is a large-span arch structure with multiple skewbacks. This tower is made of a large number of members with unique form, and contains more than five kinds of geometric features. The wind forces and the corresponding wind effects on the truss arch tower are notably complicated. In this study, wind tunnel tests were conducted to evaluate the wind forces on the steel latticed structure mentioned above using the high-frequency base balance technique. Four segmental models, including one arch foot of main truss, two arch feet of sub-truss, and one arch crown of main truss were tested in nominally smooth flow. The drag forces were measured and compared with several existing codes, including the British, American, and Chinese codes. The incidence angle effects and the interference effects on the drag coefficient were analyzed. The testing results showed that the direction of the wind forces has a marked effect on the whole truss tower. The solidity ratio and layout of the segmental models, including the cross-section and the centerline of the members, have critical effects on the drag forces.