What Is a Pile Integrity Test?

When a construction project requires deep foundations and concrete piles, it’s important to test those piles for any problems or anomalies that could affect their stability and security. Geotechnical engineers and contractors conduct pile integrity tests to ensure the safety and mechanical performance of these piles and foundations. It’s a type of quality control and quality assurance process.

Read on for an explanation of pile integrity tests and how they work.

Pile integrity tests explained

When you’re building a high-rise building, bridge or other heavy superstructure, the load needs to be transferred to lower levels of the soil. This requires drilling shafts and installing concrete piles, which will support the load.

“Pile integrity” covers certain characteristics of the structure, including the piles’ physical dimensions, continuity of the pile (are there any major cracks or voids in the pile?) and consistency of the pile material itself. Monitoring pile integrity helps prevent issues during construction, such as formation issues, soil problems, steel cage installation problems and issues with concrete placement.

One of the major challenges with testing pile integrity is that the piles are buried deep underground. That can make it hard to monitor whether the project is proceeding as planned. Over the years, methods to test pile integrity have been developed—both intrusive and non-intrusive.

How does a pile integrity test work?

Here’s a closer look at three different types of pile integrity tests:

  • Thermal integrity profiling: Thermal integrity profiling (TIP) tests the temperature variation in concrete paste as the cement cures. By monitoring the temperature, the quality management team can ensure that the cement gains the right amount of strength during the curing process. It allows engineers and contractors to monitor cement outside the steel cage, and provides real-time data. However, it can only be used on new piles, which limits its applications for projects already in progress.
  • Low strain pile testing: This test monitors the strain on impact on the head of a pile. It measures quality and integrity, but it can also help estimate the length of unknown, pre-installed piles. Engineers can monitor the pile’s consistency, integrity and depth and look for any incongruities like cracks and voids.
  • Crosshole sonic logging: This method uses water and an acoustic wave transmitter. This creates an ultrasonic profile, which can be analyzed to locate defects and determine their true extent. This is used on pre-installed tubes and piles.

As you might imagine, this is only the tip of the iceberg when it comes to pile integrity tests. The engineers and contractors responsible for their installation follow complex processes to ensure safety, quality and integrity.

If you’re commissioning a superstructure, feel free to talk to your engineers and contractors about whether they’ll be conducting pile integrity tests, what kind and why. The answers should reassure you that they’re taking all necessary precautions to produce a stable and secure structure.

To learn more about our civil engineering services, reach out to the engineers at EMC2 Inc. today. We’d be glad to schedule a consultation to discuss your project.