Real Time Monitoring of Infrastructure of Subsidence Along I-70 in Washington, PA

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Two longwall coalmine panels were mined at a depth of approximately 156 m (510 ft) beneath I-70 east of Washington, Pennsylvania such that it crossed the width of one panel at two locations. The Pennsylvania Department of Transportation (PennDoT) assumed responsibility for real time monitoring of both ground deformation and changes in highway conditions. Innovative monitoring of ground deformation was accomplished with time domain reflectometry (TDR) to interrogate coaxial cables installed in seven deep holes and an array of thirty-two tiltmeters along the highway shoulder. Surface monitoring was also conducted with global positioning system (GPS) measurements at more than one hundred locations. Tiltmeters were connected to a central remote data acquisition system that automatically recorded and stored measurements. When specified tilt values were detected, the system initiated a phone call to key PennDoT personnel who then monitored tiltmeter measurements in real time via a phone line connection. Based on this information they could alert other agencies if necessary, and intensify visual reconnaissance to determine if lane closures were necessary.

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  • 08/14/2017
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