Quality Assurance of Auger Cast Piles

The length/integrity of piles are quickly and accurately determined using sonic/ultrasonic nondestructive (NDT) testing methods. Complete or partial voiding, cold joints, narrowing (necking) of concrete piles and breaks or partial or complete narrowing due to deterioration of wood piles are conditions that effect the integrity of piles and are indicated by much shorter calculated pile lengths then predicted by as built plans.

Pile lengths/integrity are determined using a sonic/ultrasonic system that measures and records the end reflected time required for compressional, shear, flexural or torque waves generated and recorded at the top of the pile ( see schematic and records over). Pile lengths are determined using reflected wave times; the time of the reflection is a function of the effective length and velocity of the pile. The velocity is a function of the modulus value(s) or strength. Piles constructed of concrete, wood and steel have been successfully evaluated using these methods as well as walls, footings and other structural members.

NDT Corporation and Shannon & Wilson tested approximately 2500 auger pressure grouted piles for J.S. Alberici Construction Co, Inc at the St. Charles Station Casino project in St. Louis Missouri. Testing was conducted concurrent with the construction of the piles. Results were provided as pile length calculations for verification of length/integrity.