Static load testing
James Fisher Testing Services provides a static load testing service to determine the performance of a pile when subjected to a given load.
Static load tests can be used to determine the settlement that can occur at working load, or a multiple of it, and can also be used to verify the ultimate bearing capacity of a pile.
There a number of different methods of static load tests:
- Maintained load test - each increment of load is held constant for a specified period of time or until the rate of settlement falls below a specified value.
- Constant rate of penetration (CPR) test - the load is applied to the pile in order to maintain the rate of penetration at a constant speed. This method is usually conducted for determining the ultimate bearing capacity of a pile.
- Tension test - similar to maintained load test, except the purpose of this method is to determine how the pile will perform under a tensile load.
- Zone testing - this method is usually conducted after ground remediation over a large surface area.
Static load testing methodology
Loading can be applied in one of two ways; using a jack which reacts against a kentledge heavier than the required test load or using a jack which reacts against beams held down by tension piles acting as anchors.
Pile settlement is recorded using dial gauges or electrical displacement transducers. The applied load is monitored using calibrated load cells, and on up to date systems can be controlled automatically using a portable computer and a compressed air pump.