Static Load Testing

Static Load Testing is the measurement of load and deflection at the head of a pile under an applied load. 

Static Load Testing is designed to mimic the actual safe working load (SWL) that the pile will experience when integrated into the structure that it has been designed to support. The minimum test load applied during the test will be equal to 1.5 times the actual design working Load (SWL) in accordance with ICE SPERW 2016. 

Preliminary pile testing on non-working piles is undertaken in advance of pile installation to validate design parameters.  Preliminary piles are loaded to failure, which is defined as the load at which the base of the pile exceeds 10% of the pile diameter, or when the applied load is 3 times the SWL in accordance with ICE SPERW 2016.

How is Static Load Testing undertaken?

With maintained load testing (MLT), the load is applied either by jacking against a grillage and kentledge system (Kentledge Test) or by jacking against a reaction beam restrained by anchorage piles (Reaction Test). The reaction test system has the added benefit of being able to test the pile in tension as well as compression. 

The load is applied to the pile head incrementally while simultaneously measuring the movement/settlement using deflection gauges recorded to a data logger. Subsequent load increments are only applied after a specified time or induced settlement is below the specified criteria. After completing the test, the data is analysed to produce load v deflection and load & deflection v time charts that are used to verify design parameters and refine pile design.  

VESTAT Automated Pile Load Testing System 

VESTAT is Strata Geotechnics fully automated load testing system for the testing of piles in both compression and tension.  

Once the reaction system has been constructed and the test pile is instrumented the working load is simply entered into the data logger and the test started. The data logger then controls the pump to load and unload the pile, via the jack, in accordance with the specified loading cycle whilst simultaneously recording the deflections. 

The system has an integrated SIM card allowing the test to be monitored and controlled remotely, this enables the tests to continue through the night unattended resulting in quicker delivery of the test data.   An important safety feature is the additional displacement sensor which detects any abnormal movement of the reaction beam which would trigger the data logger to stop the test. 

As the test is continuously controlled and the data recorded by the data logger this removes the potential for human error and provides consistency of loading and data monitoring. 

Static Load Testing by Strata Geotechnics at Van Elle

What are the advantages of Static Load Testing?

  • This test is the most accurate method for determining pile capacities
  • Static Load Testing can be carried out in all soil conditions and on all pile types and if necessary, tension and lateral testing is also possible 
  • Automated pile load testing systems can run through the night – data can be monitored and interpreted remotely, and it removes the need for sites to be manned throughout the night 
  • The remote nature and consistency of the data removes the potential for human error, with the ability to stop tests automatically should abnormal movements of the test pile or reaction beam occur 

Common Uses

  • Gives confidence in the design and that the piles will perform in accordance with the design before integration into the structure
  • Assess pile performance (displacement) during compressive, tensile or lateral loading
  • Multiple tests supplemented by Dynamic Load tests which allow assessment for potential differential settlements across a site with variable ground conditions
  • Instrumented load tests give further information including resistance distribution along the shaft and end bearing