Improvement of Low Strain Pile Integrity Test

The low strain pile integrity test (LSPIT) is currently the most widely used method of pile integrity testing.This paper studied stress wave propagation in piles in engineering tests with finite element method (FEM).From the numerical calculation results and test signals, a location of two thirds of radius away from the source (center point) for solid piles or a distance of 90 arc away from the source for pipe piles on the top face is found to be the best location to place a sensor.The high frequency disturbing signal diminishes greatly at the recommended location when the load impulse is applied.The time difference between initial velocity signals was then studied at different locations to correct the vertical wave velocity and defect depth in some situation.