Interstate Highway Settling
In January 2019, you mentioned a project involving you monitoring the possible settling of an Interstate highway due to longwall mining beneath.
Can you share the results? Did the highway indeed settle 3-5 feet?
Curious minds want to know.
A map of the points...which were targets for mobile lidar placed along the outside shoulders on both sides...
Here are the results from the final survey, in meters (versus the initial survey)
and a plot...
We had established control monuments that we thought were outside of the mining area, one east and one west, 2600 meters apart. It is interesting to note how the distance between them got shorter over time by more than 5 cm...
We occupied those with long session static GPS, and then ran a traverse between them for each of the 10 surveys, and I believe both of them moved, and probably were not actually outside the mined area. One of those was on a bridge, the other at a welcome center/rest area across the state line. The mining later continued across the state line (monitored by someone else) and under the rest area. I heard that they cut the rest area building in half to minimize damage before the mining started. Not sure how that worked out since we didn't do that survey.
Here is one of the stations in the middle that showed the most movement...red is vertical, blue is horizontal movement
Some Pitt professors who were involved were more concerned about the horizontal movement than the vertical, said it was more damaging
@john-hamilton It boggles me that a mining company can go ahead with activities that cause surface topography changes (on land it doesn't own) on the order of a meter horizontally and vertically. I've seen photos of cracked roadway pavement, and seen discussions about the potential to change the flows of streams, but I wonder about the effects on buried utilities. I've not seen any mention of that.
Who owns the mineral rights in PA?
Thanks for sharing the results.
As for mining near a dam - wow!
Fascinating topics and discussion - and way outside my wheelhouse!