NDEVC FACILITIES
NDEVC Test Bridges
Essential to establishing the reliability of any NDE technique is a performance evaluation under actual field conditions. Bridge inspection conditions are
unpredictable and are difficult to reproduce in the laboratory. For example, the unpredictable movements of traffic and accessibility
constraints are very difficult to realistically duplicate in the laboratory. Further, any evaluation of an NDE system without including these
situational factors will likely over-estimate the reliability. Field bridges provide a test bed for investigating the impact the inspection
environment has on reliability and system performance. The field bridges are an extension of the NDEVC laboratory where additional
variables affecting reliability can effectively be investigated. The test bridges also provide a medium for assessing the physical field
suitability of NDE systems.
The selection of bridges to be included as part of the NDEVC was completed after an extensive survey of all highway bridges within 400 km of the
NDEVC. This survey included both in-service and decommissioned bridges. In-service bridges were sought to provide an active
environment where bridge inspections are normally performed. This allows many environmental and situational factors to be evaluated.
Decommissioned bridges were sought to provide a test bed where defects of known size, location, and type could be introduced without
violating the integrity of an in-service bridge while, at the same time, maintaining many of the situational factors that may affect NDE
reliability.
Two in-service bridges located near Washington D.C., were selected to be part of the NDEVC. These bridges have steel superstructures,
multiple spans, less than 15 degrees skew, and were considered ideal locations to evaluate many NDE techniques. One in-service
bridge is heavily traveled with a large percentage of truck traffic. This structure will serve as an ideal location to investigate NDE systems
intended to locate and size fatigue cracking as well as innovative sensors that detect load, stress, and deflection under live loading.
The other in-service bridge has an extremely low average daily traffic that will allow easy access to the structure for extended periods
without causing major traffic problems. The inclusion of these in-service bridges as part of the NDEVC was accomplished through
a cooperative effort with the Virginia Department of Transportation.
In 1968, the Pennsylvania Turnpike Commission (PTC) abandoned an 18 km section of the Pennsylvania Turnpike. This 18 km
section of roadway has been preserved by the PTC for the purpose of providing a location for highway related research. This section
of roadway, operated by the PTC as the Safety Testing And Research (STAR) facility, includes 2 tunnels, 5 bridges, and 18 km of
four lane roadway. The NDEVC has obtained permission from the PTC to use the STAR facility as part of its extended laboratory.
The STAR facility provides an excellent resource for evaluating the effectiveness of NDE technologies under field conditions.
The STAR facility bridges have many desirable qualities including conditions typical of the aging infrastructure, are decommissioned
which allows for structural modification of the bridges, and access is uninhibited.
NDEVC Facilities continued:
NDEVC Laboratory
Component Specimens
