01046081

Component

The drag coefficients that are provided in the 2001 AASTHO Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals address round and multi-sided shapes, which are typically used for tubular tapered poles. The drag coefficients do not appropriately address the condition of a tapered pole with a multi-sided cross section that has a large bend radius or is small in size such that the cross-section approaches a round section. A method was developed to determine the drag coefficient for multi-sided shapes that are nearly round. The proposed method uses linear interpolation between the drag coefficient for round cross sections and the drag coefficient for multi-sided cross-sections. This proposed change would impact wind loads on highway support structures composed of multi-sided tubular members, such as street lighting poles, cantilevered traffic signal mast arm structures, and high mast lighting poles. A step-by-step sample calculation is provided to illustrate the procedure for calculating the drag coefficient using the proposed method.

01042056

07-1982

English

26p

2007

Transportation Research Board 86th Annual Meeting

CD-ROM

Figures (15) ; References (7) ; Tables (5)

Coefficients; Cross sections; Drag forces; Lighting columns; Lighting equipment; Sign supports; Street lighting; Structural analysis; Structural engineering; Structural supports; Support poles; Traffic signal hardware

Signal supports; Traffic signal supports

Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls

Transportation Research Board Annual Meeting 2007 Paper #07-1982

TRIS, TRB

Feb 8 2007 6:41PM