United States Department of Transportation
ROSA P serves as an archival repository of USDOT-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by USDOT or funded partners.
As a repository, ROSA P retains documents in their original published format to ensure public access to scientific information.
i
Fatigue performance of variable message sign & luminaire support structures : volume II, fatigue related wind loads on highway support structures.
-
1998-05-01
[PDF-7.54 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final report; Sept. 1996-June 1998.
-
Corporate Publisher:
-
Abstract:In Order to determine equivalent static pressures for fatigue loads on cantilevered highway support structures a
cantilevered Variable Message Sign(VMS) located along Interstate westbound at mile marker 48.5 in northern
New Jersey was continuously monitored for three months. The structure was instrumented with strain gages,
pressure transducers, and a wind sentry. All the data was collected with a Campbell Scientific CR9000 digital
data acquisition system. A cellular phone transceiver enabled remote communication with the data logger. The
system and instrumentation was powered with solar powers and marine batteries. Short-term testing was
performed on the structure to determine the dynamic characteristics such as stiffness, natural frequency, and
percent of critical damping. Results of the short-term test indicated that the stiffness was 0.24 kN/mm, the first
and the second modes were 0.87 cycles/s and 1.22 cycles/s respectively, and the percent of critical damping for
the first and second modes were 0.57 percent and 0.25 percent respectively. Long-Term monitoring was
performed to capture the structures response to natural wind gusts, galloping, and truck-induced wind gusts. This
data would then be used to determine appropriate fatigue design wind loads for future sign support structures.
During the three months of monitoring the structure did not experience galloping, which is a phenomena highly
dependent on location. A galloping design pressure of 1000 Pa was recommended based on previous research.
The summer months, which is when the structure was monitored, were not conductive to the strongest natural
winds patterns in Northern New Jersey. The highest natural wind speed that was recorded was 7.5m/s. It is
believed that much stronger winds are present in winter and spring, therefore a natural wind gust design
pressure of 250 Pa was recommended. Truck-induced gusts were measured and a linear gradient for the truckinduced
gust design pressure was determined. The truck-induced gust design pressure ranged linearly from
1760 Pa at 0 to 6m above the surface of the road to 0 Pa at 10.1m and over.
-
Format:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
