Backfill Mystery

Backfill Mystery
Locating Conduit ..?

We were called to ensure the area was clear of high voltage conduits prior to excavation.  With our expertise and cutting edge GPR imaging equipment, it should have been a quick one-and-done.  Years of experience, however, has taught us to never underestimate a project, especially a very old concrete slab.

The good news: there weren’t any conduits under the slab. The bad news?  The subgrade was a mess of noise. Random reflections here and there, things starting and stopping randomly, nothing linking up. It as about as far from a “typical” construction layout as you can get.

We marked up what we saw…not sure anyone believed us. Excavation revealed the area below the slab had been backfilled with previous demolition debris. It was littered with chunks of concrete and rebar.

The curl in the bottom-right? Turned out to be a piece of abandoned tracer wire.