I saw this device (well, a model of it and a presentation) at a recent geotechnical conference and I was very impressed. One of the challenges with the QC of drilled shafts is that you don’t always know the condition of the bottom of the shaft. The Shaft Quantitative Inspection Device (SQUID) measures the thickness of the debris layer above the bearing strata and the strength of the bearing layer itself. The results are presented on output in numerical and graphical format in real time. The device attached to the rig’s Kelly Bar and is deployed with minimal effort. [Source: Pile Dynamics YouTube Channel. Image: Pile Dynamics]
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Drilled Shaft Rig Topples in Austin, Texas [Video]
An excavator mounted drill rig drilling shafts as part of a project to pass utilities under I-35 near 51st Street toppled over while trying to move in soft, rain soaked soil. The Austin Fire Department was able to extract the operator from the cab and he was taken to a local hospital with minor injuries, a minor miracle. I’m not sure what the purpose of the drilled shafts were for. Since the project was for some kind of utility pipe jacking under the freeway, I’m speculating it was drilling holes for temporary shoring for the jacking pit or something along those lines. I’m sure OSHA will be looking into the incident. Video news story after the break. (Photo from Austin KXAN.com).
Drilled shaft rig falls into hole – Iowa
On May 15 a drilled shaft rig operated by Mid America Drilling Corp was nearly swallowed by the 9-ft diameter hole it was drilling for a cell tower foundation near Harlan, Iowa. Fortunately nobody was injured and the truck did not suffer any significant damage.
In Arizona, the standard of practice is to use a temporary surface casing to prevent dangerous failures like that. I once saw pictures of a drilling contractor superindendent almost get sucked into a collapsing shaft, even with the temporary casing. Pretty scary stuff. Source: Harlan Tribune. (Photo by Samantha Bruck)