This test consists on the application of a load on the pole’s head and on its deformation measurement. A first kind of test is the project or pilot test, normally a thrust or breaking at a maximum at least three times greater than the working load. Its goal is to determine the pole’s load limit and to analyse its curve-breakdown.
If the pole is properly instrumented, it allows to study separately the lateral resistance, the resistance at the tip and the related transfer functions.
The acceptance test, on the contrary, is performed on poles selected at random from the palisade, during or after its construction. This test cannot be destructive, so the test load is limited to 1,5 times greater than the working load. Its aim is to check the correct processing and also the pole’s success; secondly, it could provide indirect informations about the pole’s security coefficient
Test on instrumented pole
In addition to the applied load and to the vertical drift of the pole’s top, it is possible to perform measurements of drifts and/or deformations at different depths along the pole’s stem. This kind of measurements allows to obtain informations about the development of the resistances at the lateral tip, and consequently they inhance a lot the load tests usefulness, especially the project ones. The measurements are made through special sensors (strain-gauges); the sensors are glued on the stain gauges that are in turn fixed on the pole’s rebar and then, they are drowned in the concrete. The measure is transmitted outside through cables connected to a data acquisition unity.