Pile Driving Analyzer
The Pile Driving Analyzer (PDA) from Pile Dynamics is a very useful tool for measuring and determining the effects of impacts on a pile. The impact is often applied by the pile driving hammer on a driven pile, but may also be due to the impact of a large drop weight applied to a bored or augered pile. The PDA monitors acceleration and strain sensors, which are quickly attached to the pile by bolts, and process these signals after each hammer blow during driving or restrike.
The signals are digitized by the PDA, results are computed, and the data array of the signals for a blow is stored. The data may be interpreted for pile capacity, compression stresses induced at top and bottom, tension stresses along the shaft, energy transferred to the pile or shaft, and pile integrity. The results are then analysed with CAPWAP (CAse Pile Wave Analysis Program) to further define the pile capacity.
Low Strain Pile Integrity Testing (PIT)
"PIT makes it economically feasible to verify the integrity of every pile on your site"
Pile Integrity Tester (PIT), also known as Sonic Echo or Pulse Echo methods, is used for the low strain integrity testing. It is a non-destructive testing method that applies mainly to CFA piles, bored piles and driven concrete piles. It detects potential defects such as cracks, necking, soil inclusions and voids. In some situations, the method can determine unknown lengths of piles. PIT does not require advance planning and it is most affordable option when the pile integrity is in doubt.
An accelerometer attached to the top or side of the test pile monitors the impact and resulting reflections of a small hand-held hammer. The accelerometer signal is evaluated in the field or transferred to a personal computer for further analysis by PIT-W, a Windows based analysis program. If a defect in the pile is detected along the shaft, its size and location can be estimated by analyzing the propagation and reflection of the wave induced on the foundation by the hammer impact. It is also possible to estimate the depth of the pile toe.
