Gamma Gamma Logging Services


GRL Engineers offer Gamma Gamma Logging services along with Crosshole Sonic Logging, for a comprehensive assessment of drilled shaft concrete density and integrity. Gamma-Gamma Logging (GGL) is a non-destructive test method used to assess the concrete integrity of drilled shafts. Two-inch diameter PVC access tubes are attached to the steel reinforcing cage prior to cage insertion into the shaft excavation and concrete placement. In cases where testing was not initially planned, GGL can be performed using core holes drilled through the concrete.

GRL engineers report Gamma-Gamma Logging results on a density vs depth plot in accordance with CALTRANS CT-233 test standard. For additional information on Gamma-Gamma Logging (GGL) or any other of GRL Engineers services please contact [email protected].

Benefits of GGL

  • Objectively evaluates integrity and relative concrete quality inside and outside of the reinforcing cage through a gamma-density correlation
  • Provides highly repeatable test results
  • Assesses the relative homogeneity of shaft concrete
  • Identifies location of potential shaft anomalies through statistical analysis