The Pile Driving Analyzer is the most widely employed system for Dynamic
Load Testing and Pile Driving Monitoring in the world. It assesses the capacity of several piles in a
single day. The PDA also evaluates shaft integrity and investigates driving stresses and hammer energy
during pile installation.
The PDA is available in two models, PAK and PAX. Both display
results in real time on a color LCD screen.
The light and battery operated PAX gives the engineer the
option of being present for the test or avoiding travel to the job site. When the engineer is present
for the test the PAX runs in local mode and displays all test data and results for immediate
interpretation. When only the PAX is on site a field crew sets up the test and the PAX transmits test
data via a broad band internet connection, while an engineer located elsewhere follows the test in real
time.
A testing engineer uses the PAK on site to monitor pile
installation and to estimate pile capacity at the time of the test. The PAK displays all test data
and results for immediate interpretation.
The driving hammer itself is used to perform PDA tests, or High Strain
Dynamic Tests, on pilot or production piles. If necessary, it is possible to perform re-strike PDA
tests even after the driving hammer is no longer on site, by using a drop weight (see examples) to impact
the foundation. The PDA software calculates results from velocity and force signals obtained by
accelerometers and strain
transducers attached to the pile. These sensors may be wireless if a PDA model PAX is used.
CAPWAP® analysis of PDA data is essential for a Dynamic Load Test. It provides the soil
resistance distribution along the foundation and simulates a static load test. Extensive correlations between
CAPWAP simulated and actual static load tests have proven the reliability of this method of determining
pile capacity.
Both PDA models conform to
ASTM D4945 and many other codes and specifications . The PDA software suite, consisting of PDA-W,
PDIPLOT and PDICURVES, outputs reports that satisfy ASTM 4945 requirements.
high strain dynamic testing
|
|
