Over 600 longwall panels have been mined in Pennsylvania in the last 50 years. Of those 600 panels. 25 panels undermined interstate highways. Despite this quantity of panels, much is still unknown regarding the detailed effects of undermining highways. The Gateway Mine, the Emerald Mine, and the Cumberland Mine undermined I-79 with 17 panels between 1982-1989 and 2003-2008, respectively: mine Eighty-Four undermined I-70 with 4 panels between 1987-2000. Through the examination of the panels that undermined I-70 and I-79, it is possible to determine which factors have most impacted the highway alignments. In some locations, the highway intersects with panels at angles ranging from 45 to 80 degrees, and at others, it runs between two panels, which simulates the effect of gateroads on the subsidence. The panels width to overburden ratio varies between 0.64 and 1.7, meaning that the interstates were influenced by both subcritical and supercritical subsidence basins. The face advance rates and overburden depths also vary between the panels. Unfortunately, specific information detailing highway impacts associated with unique characteristics of the subsidence basins are limited. However, using the profile function model and influence function model within the Surface Deformation Prediction System (SDPS). the effects of overburden, panel size, and orientation of the road to highway can be indirectly assessed by profile and influence models of subsidence basin formation.
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