Design Fatigue Load of Sign Support Structures Due to Truck-Induced Wind Gust

Author(s):  
Ian E. Hosch ◽  
Fouad H. Fouad
Author(s):  
Fouad H. Fouad ◽  
Elizabeth Calvert

The AASHTO 2001 Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals include revised wind load provisions and new criteria for fatigue design. These provisions and criteria differ considerably from those in previous editions of the specifications, and their impact on the design of cantilevered overhead sign supports has not been fully studied. This study assesses the effect of these provisions and criteria on the design of cantilevered overhead sign support structures with the horizontal support composed of a four-chord truss. Wind and fatigue load design calculations of typical structures, located at sites across the United States, were performed with the design provisions of the 2001 supports specifications and compared with design in accordance with the previous edition of the specifications. The induced forces in the primary members of the cantilevered sign support structure were calculated, and corresponding member sizes and weights were estimated. The results of the study demonstrated the effect of the wind and fatigue load provisions on the design of cantilevered overhead sign support structures.


2016 ◽  
Vol 43 (3) ◽  
pp. 279-286 ◽  
Author(s):  
H.P. Hong ◽  
G.G. Zu ◽  
J.P.C. King

Experimental results of the truck-induced wind gust pressure were used as the basis to develop the equivalent static truck-induced wind pressure for fatigue design in the American Association of State Highway and Transportation Officials (AASHTO). The development does not explicitly quantify the stress range distribution, nor does the development discuss the implied reliability. No recommendation is given to consider truck-induced pressure for fatigue design in the Canadian Highway Bridge Design Code (CHBDC). This study quantifies the stress range due to truck traffic, and calibrates the equivalent static truck-induced wind pressure for fatigue design of overhead steel sign support structures. The reliability-based calibration is focused on the CHBDC. For the vertical excitations, the calibrated pressure is less than 50% of that suggested in the AASHTO. For the horizontal excitations, the calibrated pressure can be greater or smaller than that for the site-dependent natural wind gusts. Therefore, the truck-induced horizontal wind pressure could govern the fatigue design for some sites.


1988 ◽  
Vol 114 (12) ◽  
pp. 2755-2772
Author(s):  
Mohammad R. Ehsani ◽  
Reidar Bjorhovde

Author(s):  
Theresa M. Ahlborn ◽  
John W. van de Lindt ◽  
Alonso J. Uzcategui ◽  
Matthew E. Lewis

Sign in / Sign up

Export Citation Format

Share Document