Integrity Testing of Piles – PIT
The integrity testing of piles, referred to in the ASTM D5882-16 standard as the Low Strain Impact Integrity Test, is a common non-destructive testing method used to assess the integrity and/or length of piles. This is a non-invasive, relatively inexpensive testing method that allows us to obtain a “picture” of the installed pile, which is buried in the ground.
Pile Integrity Testing (PIT) is conducted by striking the head of the pile with a standard hammer and measuring the time interval between the arrival of the outgoing elastic wave and the wave that is reflected from the damage or the pile tip (the wave has insufficient intensity to interpret the load-bearing capacity of the pile). Using the known modulus of elasticity of the pile material, and thus the speed of the elastic wave, the length of the pile can be interpreted. If the pile material is damaged, the reflected wave from the damage will return earlier than if it were reflected from the pile tip, indicating whether the pile was correctly constructed (i.e., whether the integrity of the pile is ensured).
Pile Integrity Testing: Methods and Equipment
The piles being tested can be concrete (unreinforced or reinforced with steel reinforcement or steel circular profiles) or jet-injected columns (reinforced or unreinforced). Concrete piles may be bored, CFA (Continuous Flight Auger), or driven. The results of the tests can be used to assess the cross-sectional area and length of the piles, as well as the integrity and continuity of the piles and the consistency of the pile material.
The testing is conducted using a highly sensitive accelerometer, a specialized pile integrity testing device (lightweight field computer), and a small handheld hammer. Testing data is collected and stored on the pile integrity testing device. Subsequently, further office analysis is performed using the “PET” (Pile Echo Tester) software.
Pile testing is conducted no earlier than when the concrete strength reaches 75% of the design value, typically around 5 to 7 days after the piles are cast.
Geokol has obtained official Accreditation for the PIT method (Pulse-echo method) for testing the integrity of piles. This accreditation is awarded by the Croatian Accreditation Agency (HAA) according to the HRN EN ISO/IEC 17025:2017 standard, and confirms the high professional and technical competence of our laboratory for non-destructive testing of construction piles.
Accreditation for the PIT method guarantees that we conduct all tests in accordance with the internationally recognized standard ASTM D5882 - 16, which ensures the accuracy, reliability and transparency of the results. This accreditation further confirms Geokol's commitment to the highest standards of quality in construction, thus providing our clients with additional security and trust. Geokol continuously invests in employee education and regularly improves the technical capacities of the laboratory in order to ensure the top quality of our services.
Accreditation for the PIT method is available on the official website of the Croatian Accreditation Agency (www.akreditacija.hr), which confirms our transparency and compliance with international standards.