Low strain integrity testing

Low strain integrity testing (also known as low strain dynamic test, sonic echo test) is a non-destructive pile testing method for integrity assessments of drilled shafts or driven concrete piles.

 

The test is performed with a hand held hammer, a sensitive accelerometer and the Pile Integrity Tester (PIT).

 

The accelerometer is attached to the top of the pile, and then a compressive wave is generated by tapping the pile head with a hammer. When the downward compression wave encounters a change in cross section, a non-uniformity of concrete, or the toe of the pile, it generates an upward tension wave that is later picked up by the accelerometer. Then the data is processed by the PIT equipment and interpreted by an experienced engineer.

 

The test is able to provide information on the magnitude and location of the major defects, and the results may also be used to estimate pile length.

 

Because of its simplicity, speed of execution and relatively low cost, the test has been routinely used worldwide for many years , and it may be performed on 100% of the piles on a given a job site.