NDT Guide – balancing the perspectives on non-destructive testing of deep foundations-PPT Presentation

PPT Presentation

Pdf Summary

The presentation outlines the development of a Non-Destructive Testing (NDT) Guide for deep foundations. The guide aims to improve how NDT methods are selected, specified, performed, and interpreted; reduce false-positive findings and foundation defects; increase awareness and acceptance of testing; and support informed evaluation before a potentially defective foundation is abandoned.<br /><br />A multidisciplinary task group—with contributors from consulting, contracting, ownership, testing, supply, and industry associations—organized the guide into six areas: purpose and scope; design considerations; NDT principles and fundamentals; applications; evaluation and assessment; and acceptance plans and resulting actions.<br /><br />The applications section covers four methods: Cross-Hole Sonic Logging (CSL), Thermal Integrity Profiling (TIP), Low Strain Integrity Testing (LSI/PIT), and Gamma-Gamma Testing. For each, the guide addresses applications, practical testing considerations, advantages, limitations, and relative costs.<br /><br />The evaluation and assessment work seeks a shared approach for North America and Europe. It emphasizes reviewing all relevant project records—not only NDT results—and clarifying who is responsible for evaluation, with findings informing acceptance decisions.<br /><br />Key unresolved issues include balancing current practice with best practice, remaining objective and technology-neutral, and deciding how specific recommendations should be when foundation conditions vary. The acceptance chapter is especially challenging: it builds on assessment, considers possible mitigation strategies, and draws on FHWA guidance, while noting limited European representation.

Keywords

Non-Destructive Testing

NDT Guide

deep foundations

Cross-Hole Sonic Logging

Thermal Integrity Profiling

Low Strain Integrity Testing

Gamma-Gamma Testing

foundation evaluation

acceptance plans

foundation defects