geophyConsult, safety & monitoring

State-of-the-art technoligies for the
safety and the monitoring of infrastructures

The HET implemented by geophyConsult

Contact

✉️

Contact

📧 lab@geophyconsult.com
📞 +33 6 47 28 62 93

Video of sample preparation (in French)

Video of the test process (in French)

Video interpretation of the test (in French)

Test deliverable (in French – can be delivered in English upon request)

Test sheet delivered by geophyConsult

Example of test use

Problem:

Following the observation of burrowing animals in the area surrounding its structures, a structure owner wonders if the presence of potential tunnels through its structures, typically 25 cm in diameter, could cause breaches.

Ordered tests:

To answer this question, the structure owner takes samples from its structure representative of the horizons likely to contain burrows and orders HET tests to be carried out on these samples.

Tests results:

The HET tests performed show that the measured critical stress is always between 45 and 70 Pa, and that the measured erosion index is always between 2.3 and 2.5.

Interpretation:

The critical stress applied along the walls of the gallery in the diagram above is approximately 125 Pa (ρxgxΔHxØ/(4xL)).

It is therefore greater than the measured critical stress (max 70 Pa).

It cannot, therefore, be ruled out that the presence of burrowing animals causes erosion of the conduit.

The Bonelli 2013 chart shown here (which estimates the characteristic time for a breach to open based on the erosion index) indicates that such a breach, if it were to begin, would develop in approximately one hour.