Pile Testing
Low Strain Pile Integrity Test
Low Strain Integrity Test, also known as Pile Integrity Test (PIT) is a non-destructive testing method for integrity assessments of concrete piles (augured cast-in-place piles, drilled shafts or driven piles). If major defects exist, test results may be interpreted to estimate the magnitude and location of defect.
Because of the simplicity, speed of execution and relatively low cost, PIT may be performed on 100% of the piles on a given job site.
The methodology involves a small impact by hand-held hammer on the pile top that generates a compressive stress wave in the pile. The stress wave propagates down the pile shaft and is reflected when it encounters either the toe or a non-uniformity of the shaft. These reflections cause a change in the acceleration signal measured on the pile top, which is picked up and processed by the Pile Integrity Tester (PIT) equipment and interpreted using PIT-Software.
STS is equipped with Pile Integrity Testers from Pile Dynamics, USA to perform Low Strain Pile Integrity test on piles.
High Strain Dynamic Load Test
Dynamic Load Testing is a fast, reliable, and cost-effective method of evaluating foundation load bearing capacity. STS can perform Dynamic Load Testing on driven piles, drilled shafts, auger-cast piles, micro piles, and other cast in place foundations. Due to less execution time, several dynamic load tests can be conducted in a single day. In addition to bearing capacity, Dynamic Load Testing provides information on resistance distribution (shaft resistance and end bearing) and evaluates the shape and integrity of the foundation element.
A Pile Driving Analyzer (PDA) with pile top force and velocity transducers are used to conduct the pile test. Two strain transducers and two accelerometers are attached to the pile head, on opposite sides of the pile to cancel bending effects during hammer impact. The signals of strain and acceleration are conditioned and processed by the PDA. Signals of pile top force and velocity are measured and analyzed during each hammer impact. At the time of testing, PDA compute static pile capacity from pile top force and velocity data. This is subsequently checked with the more rigorous signal matching technique by a computer program ‘CAPWAP’ (Case Pile Wave Analysis Program) to estimate the static load capacity of pile and distribution of soil resistance along pile length.
STS is equipped with Pile Driving Analyzers (PDA-8G) from Pile Dynamics, USA to perform Dynamic Load Test on piles.
