The dynamic loading test method allows a large number of piles to be tested in record time and at an extraordinarily low cost, which greatly improves the reliability of the data, unlike static tests alone.
The dynamic pile loading test was developed in the 1960s in North America. Its use is spreading in the Nordic countries, Japan and Latin America. Its very economic nature also attracts emerging countries that adopt it massively, sometimes at the price of the rigor of execution and analysis, and therefore the reliability and accuracy of the results.
Today, most international building codes encourage the use of dynamic loading tests. Several thousand are executed worldwide each year, including less than a dozen in France.
Eurocode 7 allows for a significant reduction in design basis safety coefficients, if these are controlled by dynamic load tests, together with a static test for each type of soil and pile.
The load bearing capacity as measured by a dynamic loading test is in good agreement with the static tests. The observed differences, generally less than 15%, are mainly due to the healing time of the soil and the choice of failure criteria.