This 17.6m (58ft) deep slurry wall element was cast in place and installed with three steel tubes.
The contractor use polymer slurry from unknown source...
A diagonal defect at a depth of -5m to -6m between access tubes 2 and 3 was correctly detected using CHUM.
The image below is a B&W fuzzy-logic tomography. It takes just a few additional minutes to log this data compared to one-dimensional CSL.