Development of pile driving instrumentation for bearing capacity determination of driven or drilled (in the case of dynamic loading tests) piles, started in the 1950s. This technology also allows, by numerical acquisition of the waves generated by the driving (stress and acceleration waves) to control:
- The efficiency of the installation hammer,
- The soil behavior during driving,
- The stresses in the pile.
Pile driving instrumentation offers many advantages but also has certain limitations. By substituting traditional static load tests with dynamic load tests or instrumentation during driving to determine the axial capacity of a pile, it has been possible to considerably reduce the cost and time of execution. This is particularly true for the control and validation of offshore piles.
However, the standard pile driving monitoring does not allow precise measurement of the distribution of resistance along the shaft and provides only a rough estimate. The stresses generated along the pile shaft during driving are calculated based on measurements made at the pile head and hypotheses of soil dynamic behaviour. The knowledge of these stresses and their distribution along the pile are necessary to determine the fatigue accumulated by the steel during driving, or to control and reduce the risk of damage pile toe.