Purpose of Dynamic Pile Testing (DPT)
The Pile Driving Analyzer® (PDA) is used worldwide in the evaluation of both driven piles and drilled shafts. PDA results can be obtained faster and more economically than traditional static pile load tests. DPT methods have the ability to test many piles or shafts per day at a fraction of the cost of traditional testing methods. DPT also provides information on driving stresses in the pile, pile integrity, performance of the driving system, and other factors affecting the foundation.
DPT methods are particularly useful on small projects where traditional load tests are not normally economically feasible. On large projects or areas with highly variable soil conditions, numerous DPTs can be performed to provide more information at the site. This helps to minimize potential construction problems and costly delays, and helps to prevent "over design" of foundation. DPT applications during construction can help identify problems early thereby helping to prevent costly delays, increase efficiency, verify pile integrity, and assure quality control.
Our DPT Capabilities
Eustis Engineering was the first private consulting firm to own and operate DPT equipment in the States of Louisiana and Mississippi. We dynamically test many pile types including timber piles; steel H-piles; square, precast concrete piles to large (60 to 72-in. diameter) spun-cast, prestressed, concrete piles; and steel pipe piles. We operate two standard (PAK units) Pile Driving Analyzers® and one battery operated portable (PAX unit) PDA.
To support our three PDA units, we have an extensive inventory of calibrated gauges. This inventory consists of 28 strain gauges, seven waterproof strain gauges, 23 piezo-electric accelerometers, six piezo-resistive accelerometers, three waterproof accelerometers, and six wireless transmitters. In order to ensure field data quality and assist the field PDA testers, all PDAs have a wireless modem.
Other Non-Destructive Testing Capabilities
Our engineering staff at Eustis Engineering also performs other non-destructive testing services on piles and shafts, including crosshole/single-hole sonic logging (CSL or SSL) and low strain pile integrity testing (PIT). To perform CSL or SSL tests, Eustis Engineering uses a Crosshole Analyzer (CHA) system manufactured by Pile Dynamics Inc. Eustis Engineering has performed CHA and PIT on a variety of pile types and sizes such as small (12-in.) diameter augercast piles and large (5-ft.) diameter drilled shafts.