ASTM D5882 Requirements for Pile Integrity Test

Pile integrity test is to serve as a screening process to identify acoustically anomalous piles. It is low strain dynamic test (a light impact is applied to a pile it produces a low strain) based on wave propagation theory. The impact produces a compression wave that travels down the pile at a constant wave speed. Changes in cross sectional area - such as a reduction in diameter - or material - such as a void in concrete - produce wave reflections.

This procedure is performed with a hand held hammer to generate an impact, an accelerometer or geophone placed on top of the pile to be tested to measure the response to the hammer impact, and a data acquisition and interpretation electronic instrument.

These tests shall be performed in accordance with ASTM D5882 “Standard Test Method for Low Strain Integrity Testing of Piles”. The requirements of this standard are:

Item	Description	Requirements
5.1.1.	Impact force application	Hammer with hard plastic tip
5.2.1.	Accelerometer linearity	Up to 50 g
5.2.1.	Accelerometer time constant	≥0.5 sec
5.2.1.	Resonant frequency	≥ 30 kHz
5.2.1	Calibration accuracy	5%
5.3.	Signal transmission	Low-noise shielded cable
5.4.1.	Apparatus	Permanent graphic display
5.4.1.	Apparatus	Permanent data storage capability
5.4.1.	Apparatus	Blow averaging capability
5.4.1.	Apparatus	Variable amplification
5.4.1.	Apparatus	Filtering capability
5.4.2.	Recording apparatus	12 bit A/D resolution
5.4.2.	Sample frequency	25 kHz
5.4.2.	Clock jitter	≤0.01%
5.4.4.	Signal duration scale	2 L/c plus 5 msec