PDA Testing is used to provide data on strain or force and acceleration of a pile under an
impact force. The data is used to evaluate the bearing capacity and the structural integrity of the pile
as well as hammer performance, pile stresses and soil characteristics, such as soil damping
coefficients and quake values.
Pile integrity, which is accurately evaluated on site, would allow the engineer to accept/reject the pile immediately.
PIT is a quick and cost effective method to evaluate the shaft integrity of cast-in-situ piles. The testing is able to provide information on:
a) physical dimension
b) pile continuity
c) consistency of material
Low Strain Pile Integrity Testing is normally carried out on cast in-situ piles. Driven piles are also able to be tested the right condition. The effectiveness of the system is limited to a pile length not exceeding 30 to 60 pile diameters depending on soil condition and concrete quality.
CHAMP is used to detect defects in cast in-situ bored piles caissons, barrettes and diaphragm walls.
When cast in-situ piles are constructed, the following defects may occur, hence the main objectives
in the testing is to provide the client/consultants information about :-
a) honeycombing due to inadequate vibration.
b) segregation due to over vibration and improper concrete placement methods.
c) washouts of cement due to groundwater flow.
d) cracks in pile shaft due to shrinkage.
e) inclusion of foreign material causing contamination of the concrete.
f) necking of the pile due to collapse of side walls during withdrawal of the temporary
The force and velocity data obtained in the field by the PDA is processed and a representative blow will be used for further analysis using the CAPWAP suite of computer software. A typical outputof the CAPWAP results will be :-
a) Total computed soil capacity
- sum of Skin Friction and Toe Bearing
b) Computed load against settlement curve
c) Resistance distribution along pile shaft
This tool is used for monitoring ground/ structures vibration emission levels. The results obtained are in the form of Peak Particle Velocity (PPV). The PPV obtained is compared to the allowable emission levels for the particular structures evaluated.
Sound monitoring is also similar to vibration measurements. It measures the maximum noise level at the transducer location. This results are then compared to the recommended levels by the local authority or the environmental noise and vibration emission limits.
Non destructive testing of welds using Ultrasonic Examination to quailfy welding procedures and to ensure
quality of finished welds.