Pile Integrity Testing: Key Requirements for Reliable Foundation Assessment

Pile Integrity Testing (PIT) is a critical non-destructive method used to ensure the quality and reliability of deep foundations. Whether you’re working on bridges, high-rise buildings, or industrial projects, understanding PIT requirements is essential for structural safety and compliance.

Pile Integrity Testing evaluates the physical condition of foundation piles to detect defects such as cracks, voids, necking, or inclusions. The most common method is Low Strain Impact Testing, standardized under ASTM D5882.

In this post, we want to highlight some important aspects that are lesser known and sometimes neglected.

Influencing factors on PIT assessments

To draw correct conclusions, it is paramount that the analyst receives the following information prior to testing:

1. Pile Design
2. Pile Layout Drawings
3. Drill Logs
4. Geotechnic Reports
5. Pile Cards
   • It is critical for the analysis that Pile Cards contain correct information.
   • Pile Cards should include the following information, although not limited to:
     • The pour date
     • The pile’s bottom RL
     • The pile’s top RL (as tested)
     • Theoretical concrete volume
     • Actual used concrete volume
     • Design concrete strength
     • Borehole shaft information, e.g. was a collapse observed
     • Any observation If any of the provided information is incorrect, an analyst may arrive at a different assessment conclusion.

Core Test Requirements

To ensure best results, PIT must meet specific technical and procedural requirements.

1. Timing
   • Conduct tests no earlier than 7 days after casting or when concrete reaches ≥75% of design strength.
     
2. Top of Pile Concrete Quality
   • The quality of the pile’s top section must be of the same quality as the rest. Any possible weaker concrete on the top of the pile due to the construction method must be removed.
     
3. Surface Preparation
   • The pile head must be clean and dry.
   • Loose concrete and debris must be removed.
   • The surface must be prepared to the provided specifications prior to testing.
     
4. Number of piles to be tested
   • The ASTM D5882 states that the number of piles to be tested should be specified by the engineer.
   • The best practice is to test 100%.
   • A common practice is:
     • for small foundations of up to 20 piles to test all piles. 
     • for larger foundations to test at least 20 piles and thereafter 10% of the remainder, or at least 3 piles of any given pile type 

Conclusion:

Pile Integrity Testing is more than a compliance step—it’s a safeguard for structural integrity and project success. It enables engineers to detect issues early, optimize designs, and ensure long-term reliability.

Have questions about Pile Integrity Testing call CSI.

We would be keen to hear what NDT solutions you would like for your structural resilience investigations.
If you would like to find out more about the Non-Destructive Testing Services (NDT) that we offer click here!
Click here for a list of our services.
Call Us On 0800 33 77 67 Or Request a Quote Here.