Static Load Testing is the measurement of load and deflection at the pile top. The test is designed to mimic the actual ‘worst case’ load stresses the pile will experience when integrated into the structure it has been designed to support. The load is applied either by jacking against a grillage and kentledge system (Kentledge Test). Or either by jacking against a reaction beam restrained by anchorage piles (Reaction Test). The latter, is considerably cost effective and is able to test both pile in tension and compression. Measurements from the load cell and deflection gauges are recorded on a data logger from which information on load v deflection and load & deflection v time can be produced. Piles can also be tested in tension and laterally.
VE-STAT 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. This is controlled 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. Therefore, the potential for human error is removed, providing consistency of loading and data monitoring.
Geotechnical Instrumentation can be cast into the test pile which allows a variety of parameters to be monitored and recorded during load testing.
Strain Gauges can be installed along the reinforcing cage and monitored during compression load testing. Calculating the force experienced at each strain gauge depth enables the distribution of shaft friction along the shaft to be estimated and also the load transferred to the pile toe.
Load Cells can be cast at the base of the test piles and the end bearing resistance measured during load testing.
Inclinometer casing can be cast along the pile shaft and the lateral deflection profile measured during Lateral Load Testing by an inclinometer probe.