Atlanta PWR and Rock Socket

Project Location: Norcross, Georgia

Overview: In and around Atlanta, we have red clay and PWR (partially weathered rock). The practice here is to case through the PWR so the Engineer can verify full solid contact on rock after drilling to refusal. This often degrades the side shear in the PWR zone. One solution is to use ACIP piles as was done on a project in Norcross, GA.

On this project, Berkel and Company Contractors used a single #20 bar and our 1,000 ton and 500 ton jacks, respectively, in two separate piles to test both the sound rock and as a bonus, the side shear capacity in the PWR. Each pile was excavated to auger refusal. Then the center bar with attached jack and multiple strain gage levels was inserted into the wet grout. After 7 days of curing, the tests were run to determine the capacity of the shear in the various soil strata.

The tests were both very successful demonstrating unit end bearing values in excess of 300 ksf.  The tests also verified that the PWR resistance is far from negligible. The tests both reached the maximum capacity of their respective jacks while still mobilizing the pile enough to yield valuable data. Put another way, two very efficient tests were completed with smiles all around. We would like to thank the whole team at Berkel for their help during the entire project. It was a pleasure working with them.

Drilling the 24-Inch pile
Test piles were reinforced with single #20 bars
Test day.

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