Jan Maertens is a name like a bell in the geotechnical world. Both in Belgium and the Netherlands, as well as internationally, his contribution was appreciated. He had built up his practically-oriented expertise in a very diverse career path. It all started at the Rijksinstituut voor Grondmechanica, where, as a young engineer under the tutelage of Prof De Beer - godfather of soil mechanics in Belgium - he was able to build up and deepen his theoretical knowledge. He could later use and further develop this knowledge in practical consultancy for Belgian government construction projects in the Bruggenbureau, where he could learn from Prof Raedschelders' no-nonsense approach.

His contacts with the contracting world then led him to carrying out studies and monitoring construction projects at the firm Smet Boring. There he was able to learn to manage geotechnical problems from the executors' point of view. There, he recognised the value of thorough execution on site and therefore also took the time to learn from the practical experience of the drillers. It remained a good habit in his subsequent career to have a chat with the technicians at yards.

This dual approach, as a client and as a contractor, made Jan the perfect fit for a geotechnical consultant. The next logical step was therefore to set up a geotechnical engineering consultancy firm himself. In that context, he was involved in designing several large projects and solving geotechnical problems and damage cases. You could always turn to Jan for solidly based and practically oriented solutions.

Another important facet of Jan's career is his never-ending commitment to sharing his knowledge, both in academia as a professor at KU Leuven, and in professional societies: the ie-net Geotechnical Expert Group (Flemish Engineering Association), the BGG (Belgian Grouping for Soil Mechanics and Geotechnics), RockEnGeo (Belgian Society for Engineering Geology and Rock Mechanics), the BGS (Belgian Geosynthetics Society), and the BVOTS (the Belgian Society for Underground Engineering and Urban Planning). Of the ie-net expert group Geotechnics, the BGS and the Belgian Committee of Engineering Geology (which later, together with the Belgian Grouping of Rock Mechanics, becomes RockEnGeo), he has been chairman. In this capacity, he organised numerous study days and gave many lectures and training courses himself, always from a practical but also theoretically based point of view.

Jan was also active in international fora, including the ISSMGE working groups (chairing TC211 Ground Improvement for 8 years), the European standards committee CEN TC288 ‘Execution of special geotechnical works’ (chairing the European standards committee for micropile technology, Belgian representative in the standards committee for ground anchors...).

The connection of geology and geotechnical engineering were also self-evident to Jan. Witness among others his important contribution to the creation of the soil mechanics maps, an analogue precursor of DOV (Databank Ondergrond Vlaanderen).

[A long shot of a dirt road Description automatically generated] Listing all Jan's merits for the geotechnical world would take us too far, but one thing is certain: you could always count on clear and no nonsense contributions. The motto of writer Herman Teirlinck ‘Better shunned for my truth than wanted for my appearance’ was honoured by Jan. Diplomacy was therefore not his strongest gift, but if you got to know him better, you felt the warm heart in Jan. And that is how we want to remember Jan, as a passionate geotechnical expert and a warm human being.