Fatigue Analysis of Overhead Sign and Signal Structures. Physical Research Report No. 115.

摘要

The unexpected failure of an overhead sign or signal structure could result in serious injuries, property damage, and/or increased traffic congestion and accidents. Overhead structures intended to support signs or traffic signals are designed to resist dead loads, live loads, ice loads, and wind loads. Dead loads include the weight of the member, signs, traffic signals, or other attachments. Live loads are defined as walkways and service platforms. Ice loads are used in areas of the country where winter ice buildup is expected. The wind load is idealized as a maximum pressure based on mean recurrence intervals of a maximum wind speed for the location of service, member shape, and height above ground of the member being loaded. All loads are considered to be static for design purposes.