The dynamic load test (DLT) is performed by Fountest Engenharia using the PDA (Pile Driving Analyzer) equipment, which can be performed on all types of piles (precast, metal, wood or excavated).

The PDA is the best and most reliable equipment on the market for performing this service. Never forget to check the calibrations of the force and acceleration sensors, which must be up to date in accordance with NBR 13208:2007 – Piles – Dynamic load test, as well as the calibration of the PDA itself in relation to the force and speed channels, which can be checked at each test start and must be in accordance with ASTM D4945-17 (2% tolerance), showing the quality status of the device that is performing the measurements on your site.

It is possible to perform automated, highly reliable denial and rebound collection using equipment developed by Fountest Engenharia for this purpose.

In driven piles, the dynamic loading test can be performed during driving or re-driving, providing valuable information for the design of foundations and the evolution of the driving service, using the pile driver available on site. The ECD provides:

• Evaluation of loads mobilized at the soil-pile interface (pile load capacity)
• Measurement of tensile and compressive stresses along the pile
• Determination of efficiency parameters of the percussion system (helping to determine more productive or safe hammer drop heights)
• Evaluation of the integrity of the structural element

Subsequently, the signals collected in the field are analyzed with the CAPWAP Method, confirming information for the presentation of the results in a report, such as the simulated load vs displacement curve of a static load test.

The product of this service, a dynamic load test report, includes all items recommended by the Brazilian standard, in addition to load mobilization through RMX vs. DMX curves in the test with increasing energy, among other analyses that may be presented if necessary (such as load gain analyses in relation to time, also known as the set-up or healing effect, very useful in the analysis of off-shore piles).

The contractor must require that the test report follows, at least, NBR 13208:2007. To this end, in addition to several requirements regarding the performance of the test on site, the test report must present:

• General data: identification of the work, test location, supplier or executor of the pile, drilling data and reference to NBR13208:2007
• Pile driver data: hammer mass, material and dimensions of the stump and cushion, material and mass of the cap, description of the extension, pre-drilling equipment or special arrangement for applying the impact force
• Data on the tested piles: identification and location, workload, type, material, geometry, adaptations at the top and tip, internal reinforcements and test results on the pile material
• Pile execution data: date of execution, volume inserted in excavations, pressure, joints, driving diagram, negation at the end of driving and in re-driving, height of fall of blows, cause and period of any interruption of the pile and abnormalities)
• Dynamic test data: description and calibration data of instruments and equipment used, test date, dynamic modulus of elasticity, specific weights, wave propagation speed in the pile and its method of determination, driven lengths and below the sensors, negatives in the test, maximum values of compression and traction stresses, displacement and maximum energy transferred in the analyzed blows, description of the model and parameters of the numerical method (CAPWAP) used in the analyses, comments on the integrity of the pile and graphical representation of the signals obtained, mainly those representative of load capacity or anomalies

The Engineer who performs tests for Fountest Engenharia has an international proficiency certificate issued by the manufacturer Pile Dynamics, Inc. and PDCA (Pile Driving Contractors Association).