High strain dynamic load testing for drilled foundations
The Pile Dynamics Analyzer - Dynamic Load Tester (PDA-DLT) was designed specifically for quality assurance testing of drilled foundations, including drilled shafts, bored piles, ACIP and CFA piles. The PDA-DLT allows for multiple configurations of force measurement. The system acquires data from accelerometers and strain transducers attached to a pile or shaft so that High Strain Dynamic Tests (ASTM D4945) may be performed. The tests require the impact of a suitable drop weight.
The PDA-DLT evaluates:
- Bearing Capacity
- Structural Integrity
- Foundation Stresses
High Strain Dynamic Load Test with the PDA-DLT
The PDA-DLT assesses bearing capacity and structural integrity. Preliminary field results are further analyzed with CAPWAP® software, for results that correlate very well with static load tests. High Strain Dynamic Load Tests may be performed on drilled shafts, continuous flight auger, or castin-situ piles. The PDA-DLT makes drilled shaft testing easier with the option of conducting the test with four or more wireless strain transducers. The system can also be used to collect data in accordance with ASTM D7383 for Rapid Load Testing.
- Top transducer method eliminates concrete build up or excavation, while improving accuracy and reducing labor costs.
- Force measurements may be taken via load cell/dolly, traditionally or from ram measurements.
- Optimized for a small number of blows with variable drop heights.
- Set is measured after each impact.
PDA-DLT Software
The PDA-S software operating in DLT mode streamlines data collection and analysis for drilled shaft (bored pile) testing. File set-up includes the ability to model force measurements taken on the pile, a load cell, or the ram. Inertial effects are automatically accounted for when testing with the load cell or ram instrumentation.
Data collection allows the user to note individual drop height and set values for each impact as well as an automatic tabular summary of measurements for all blows. Additionally, force vs. displacement curves may be plotted for each impact PDA systems include licenses of CAPWAP® GRLWEAP and of the PDA software suite, including PDA-S with iCAP® and PDI-Curves.
CAPWAP uses force and velocity records measured by the PDA sensors to, by signal matching, determine resistance distribution and dynamic soil response and simulate a static load test. Hundreds of comparisons demonstrate the very good correlation of CAPWAP analysis of PDA data is the standard of practice for Dynamic Load Testing.
GRLWEAP can be used to select a hammer for efficient installation or to evaluate the suitability of a drop weight system for the Dynamic Load Test of a drilled shaft.