Pile Integrity Testing
Pile Integrity Testing (PIT) is used to assess the length and physical condition of existing piles and bored piers. This provides a quality assurance function for new installations & assists with capacity assessment of older structures. Pyramid Engineering predominately uses this method during evaluation of road and rail bridges, and to estimate the depth of unknown footings.
Pile integrity testing is performed by coupling a high sensitivity accelerometer to a measurement unit and striking the top of the encasement with a hammer of known mass. The unit measures the stress wave reflections of the hammer blow into the pile and the corresponding reflection at the pile toe. Discontinuities and changes in pile diameter produce their own individual signatures shown as stress wave reflections on the measurement unit. The resultant stress wave graph displayed is known as a reflectogram.
A pile with no discontinuities and a clear reflection at the base of the pile (known as the pile toe) can be seen in the figure below:
A pile with no discontinuities and a clear reflection at the base of the pile (known as the pile toe) can be seen in the figure below:
A pile with issues produces reflections at points other then the the pile toe as shown below.