SUCCESSFUL ENGINEERING DEVELOPMENTS
Pile
Integrity
Testing
For over 30 years we have provided reliable, practical risk management solutions that cover the geotechnical, material and environmental risks for local and international developments.
Discover unwanted anomalies with Specialised Pile Integrity Testing
Over the past 20 years Geosure have invested substantial time and effort in developing pile integrity testing skills in South Africa. With the support of NDT Technology in the UK, local personnel have been trained abroad to operate the equipment and evaluate test results. The stature of testing together with the level of skill and experience achieved has established Geosure firmly as the leaders in this field in Southern Africa.
At present it is acknowledged that in South Africa, Geosure has developed and pioneered integrity testing to the point where most piling contractors and many consultants accept the test results with confidence.
The integrity testing service offered by Geosure is considered by many contractors and clients in the marketplace to add significant value to piling contracts, particularly as such testing provides a rapid and relatively inexpensive means of screening the structural integrity of all piles on a site, as opposed to testing a select few piles using pile load tests.
Where acoustic anomalies are identified in test results, further investigation of the piles in question may be required
PET - PILE ECHO TESTER
- Mhlatuze, Mtunzini and Empangeni Bridges, N2 Upgrade, Durban
- Oceans Development, Umhlanga, Durban
- The Arch, Umhlanga, Durban
- Wilge Bridge, Harrismith
- New Solar Park, Kathu, Northern Cape
- Berg River Boulevard Bridge, Paarl, Cape Town
- N7 Upgrade, Malmesbury, Cape Town
- Northern Aqueduct Bridge over the Umgeni River, Durban
- International Convention Centre, Mbabane, Swaziland
- Zimbali Forest Lodge, Zimbali
- Maphobeni Bridge, Swaziland
- Sasol, Secunda
- Aveng Grinaker
- China Harbour Engineering Company
- China Road and Bridge Corporation
- Dura Soletanche Bachy
- Frankipile – Keller Group
- JC Geotechnical Services
- Megapile Coastal
- Megapile Inland
- Pilecon
- Siyabora Piling
- Stefanutti Stocks Geotechnical Piling
- Stefanutti Stocks Geotechnical Piling
- Wepex Geotechnical
Pile Tapping - Frequency Response and Pulse Echo Test
Pile Tapping - Frequency Response and Pulse Echo Test
The tests can be implemented on all types of individual cast insitu piles of 250mm diameter and upwards and is a non-intrusive test. The tests are based on locating impedance along the pile shaft by using vibration waves at the top of the pile formed by striking the pile top with an impulse hammer (refer to Figure 1) whilst simultaneously measuring its vibratory response.
When the signal is processed in the time domain the test is called the Sonic Echo Test, and the Frequency Response Test in the frequency domain. The frequency response graph provides the most comprehensive integrity information whilst the sonic echo tests are only used to complement the information obtained from the frequency response tests on selected piles.
These tests have a depth limitation, typically 30 to 35 times pile diameter that are usually dependant on soil conditions. The results are then downloaded and computed in the office, and changes in impedance are related to physical features of the pile, taking into account piling methods, material properties and subsoil conditions.
Sonic Logging
Sonic Logging provides a method of assessing the homogeneity of concrete in piles or other mass foundation, such as diaphragm walls. Sonic logging has no inherent limitations on penetration depth of the size or shape of structure, which can be tested. No direct access is required to the concrete surface and the method can be used to test structures with low cut off levels at an early stage. Access tubes have to be cast into the structures to facilitate the tests and pre-selection of units to be tested is therefore necessary.
The tests are directed towards anomalies identified within a group of results, which may warrant further investigation.
For the ultrasonic test at least two tubes, either plastic or steel of minimum diameter 50mm, are cast in the pile (steel tubes are preferable as these are more durable, are less likely to be damaged and less prone to debonding with the concrete). The tubes must be completely filled with water to act as an acoustic coupling agent between the probes and the tube wall. A transmitter of ultrasonic pulses is lowered in one of those tubes and a receiver in another until they reach the base of the pile. Both the transmitter and receiver probes are connected to the CHUM software (a ruggedized pen computer), which records the first arrival time (FAT) and the energy attenuation as the probes are simultaneously raised to the top. As long as the FAT and the energy attenuation are relatively constant, one may deduce that the concrete quality is also uniform and the pile is therefore acceptable.
- Mhlatuze, Mtunzini and Empangeni Bridges, N2 Upgrade, Durban
- Oceans Development, Umhlanga, Durban
- The Arch, Umhlanga, Durban
- Wilge Bridge, Harrismith
- New Solar Park, Kathu, Northern Cape
- Berg River Boulevard Bridge, Paarl, Cape Town
- N7 Upgrade, Malmesbury, Cape Town
- Northern Aqueduct Bridge over the Umgeni River, Durban
- International Convention Centre, Mbabane, Swaziland
- Zimbali Forest Lodge, Zimbali
- Maphobeni Bridge, Swaziland
- Sasol, Secunda
- Aveng Grinaker
- China Harbour Engineering Company
- China Road and Bridge Corporation
- Dura Soletanche Bachy
- Frankipile – Keller Group
- JC Geotechnical Services
- Megapile Coastal
- Megapile Inland
- Pilecon
- Siyabora Piling
- Stefanutti Stocks Geotechnical Piling
- Stefanutti Stocks Geotechnical Piling
- Wepex Geotechnical