Services / Bi-Directional Load Testing

The GRL-Cell is a high capacity device installed within a deep foundation to statically load test the foundation. As the GRL-Cell is pressurized, it loads the foundation element in two directions. The portion of the foundation element above the cell location is pushed upward against its shaft resistance. At the same time, the foundation element below the cell location is pushed downward against its shaft resistance as well as against the toe bearing or “base resistance.” Shaft and toe movements as well as embedded strain gage instrumentation are monitored for each applied load. An estimated top load movement curve is constructed from the measured shaft resistance load-movement and base resistance load-movement responses. 

Bi-Directional Test Benefits include:

  • High capacity static load test method for drilled shafts, bored piles, barrettes, and ACIP/CFA piles.
  • Separates soil/rock resistance and movement data for shaft and toe. 
  • Determines magnitude of the mobilized shaft and toe resistances. 
  • Embedded strain gauges within the foundation determine the soil/rock resistance distribution along the foundation length for optimizing the foundation design. 
  • Not restricted by structural or geotechnical limit of load frame, reaction beams, or reaction piles.

Contact us for additional details on the GRL-Cell, manufactured and calibrated in Cleveland, OH.


Enter the capacity you wish to mobilize, in Tons:

What type of test do you wish to perform?

What is your bearing strata?

Find out which APPLEs meet your needs, then contact the GRL office that serves your project location to discuss your specific project requirements.

Standard GRL-Cell Details*

GRL-Cell Capacity (tons) Maximum Test Load (tons) Outside Diameter (inches) Maximum Stroke (inches)
350 700 12 9
500 1000 15 9
750 1500 18 9
1100 2200 21 9
1500 3000 24 9
2000 4000 28 9
3500 7000 36 9

*GRL-Cell sizes are subject to change.

Learn More: