Details:

Creators:
Consolazio, Gary R. ; Johns, Kevin W. ; Dexter, Robert J.
Consolazio, Gary R. ; Johns, Kevin W. ; Dexter, Robert J. Less -
Corporate Creators:
New Jersey Department of Transportation
Corporate Contributors:
Lehigh University. ATLSS Engineering Research Center
Subject/TRT Terms:
[+]
Fatigue (Mechanics) Structural Supports Structures Traffic Signs Traffic Signs And Signals--New Jersey--Aerodynamics Variable Message Signs Wind Wind-pressure
Publication/ Report Number:
FHWA 1998-010
Resource Type:
Tech Report
Geographical Coverage:
New Jersey
Edition:
Final report; Sept. 1996-June 1998.
Corporate Publisher:
New Jersey. Dept. of Transportation
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:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:5a1932a405980a0aa59ed5dbbf9977235afde2af48cbeb94719d25fa4c94099b
Download URL:
https://rosap.ntl.bts.gov/view/dot/18369/dot_18369_DS1.pdf
File Type:

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