The Testconsult Foundation Testing department is able to offer a complete range of pile integrity testing solutions, to suit the information required by our client. We operate mainly in the UK but also overseas to provide testing services direct to the client or in support of our agents. We are able to provide technical proposals for all size of project and offer a rapid and impartial service to our clients worldwide.
TDR Method
Pile integrity testing using low strain tests such as the TDR (Transient Dynamic Response) method, is a rapid way of assessing the continuity and integrity of concrete piled foundations. It has been used in the UK since the early 1970’s, and Testconsult was the first company in the UK to obtain UKAS accreditation for this test. We use the latest portable PIT system, the TDR2, which operates in the time and frequency domain and is able to carry out advanced interpretation of data. The test measures:
- Pile length, or depth to anomalies
- Pile head stiffness
- Pile shaft mobility – which is dependant on pile section and concrete properties
The software also produces computer simulations and impedance profiles of the test result, to analyse in detail any intermediate pile shaft responses.
The TDR test requires minimal of preparation and is able to find defects corresponding to cracks, reductions in section and zones of poor quality concrete
Sonic Logging
Sonic logging is based on measuring the propagation time of an ultrasonic sonic signal between two vertical metal tubes cast into the pile during construction. Concrete containing soil inclusions, gravel, bentonite or honeycombing has a much lower propagation velocity so that the presence of these irregularities is immediately obvious.
The test is by no means new, and was developed in the 1960’s. However, since then there have been many improvements to both the hardware and software, the main ones being the rapid digitisation of signals and digital storage of all data. More recently 2-dimensional and 3-dimensional tomographic software has been developed to give a quick visualisation of areas with anomalies.
Testconsult uses the very latest sonic logging equipment to carry pout testing on contracts in the UK and Overseas.
Parallel Seismic
It occasionally happens that doubts about the integrity and length of piles arise only after the structure is complete. The pile heads are no longer accessible and other non destructive test methods are of little use.
The Parallel Seismic test was developed for checking the integrity and length of piles in this situation. The method consists of installing a closed end tube adjacent to and deeper than the pile or structure under test. A piezo electric probe is used to measure the transit time of a shock wave travelling through the pile, as it is raised in 50cm vertical steps.
A change in the rate of signal arrival time increase with depth indicates either the pile toe or a discontinuity in the shaft.
Data Sheets
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