Pile Driving Analyser

Due to cost and time restraints, usually testing is only undertaken on a very small number of piles. With the Pile Driving Analyser (PDA) you can test many more piles at a much lower cost. The PDA helps to quickly evaluate the integrity and bearing capacity of the entire pile installation by monitoring hammer and drive system performance, driving stresses, pile integrity and by assessing pile capacity. The PDA measures the acceleration and strain using electronic sensors that are attached near to the pile head, and processes these signals after each hammer blow. The signals are digitised by the PDA and the results interpreted using rigorous stress-wave analysis techniques.

Pile Integrity Tester

The Pile Integrity Tester is used for bored piles, driven concrete piles, caissons or cast-insitu concrete foundation elements. It detects potentially dangerous defects such as major cracks, necking, soil inclusion or voids. Low-strain compressive impact waves are generated by tapping the pile top with a hammer. When the downward travelling compression wave encounters a change in cross-section or in concrete quality it generates an upward travelling tension wave, which is later observed in the top pile. The velocity records from either the pile toe or from pile discontinuities, which are graphically displayed along with subsequent reflections. The location of a defect can be estimated from the assumed wave speed, and the size estimated from the magnitude of the early reflection.

Cross-hole Analyser

The Cross-hole Analyser (CHA) tests the concrete quality of recently constructed bored piles or any cast-insitu concrete foundation units using pre-installed steel or PVC access tubes placed around the perimeter of the reinforcing cage during construction. The CHA can detect cracks, concrete contamination, necking, honeycombing, voids and segregation. A transmitter and receiver are placed at the top of two parallel water-filled tubes and then lowered together to the shaft bottom, while sonic/ultrasonic waves are transmitted between the tubes at intervals of a few inches. As the sensors are being lowered, the CHA records the time that the signal takes to travel from the transmitter to the receiver, as well as the signal energy. These two quantities are indicative of concrete quality between the pair of tubes at a particular depth. A log of the drilled shafts over depth is recorded and defects or weak concrete can be identified.