From idea to product: the contribution of LSF kit experimentation

Appearance cages. Structural electrowelded mesh gabionsTechnical, architectural and sustainability aspects-Turin

12 February 2026

The role of experimental tests in the certification of Dry Foundations

17 March 2026

In order for the idea of a prefabricated foundation, made with a gabion of electrowelded mesh filled with pebbles, became a structural product for civil engineering, it was necessary to carry out a robust experimental campaign involving, for about 3 years, a research group distributed over two departments of theUniversity of Trento (Department of Civil, Environmental and Mechanical Engineering-DICAM and Department of Industrial Engineering-DII) and theInstitute for Bioeconomics of the National Research Council., based in San Michele all'Adige (TN). In the Materials and Structures Testing Laboratory (LPMS) of the DICAM tests were performed to study the mechanical behavior of the LSF kit., in order to optimize its geometry, identify the tests to be included in the EAD (EAD 200171-00-0103) and obtain CE marking through ETA.

Mechanical behavior of the kit: breaking domain and stiffness

The mechanical behavior of the kit under monotonic loads is described through the failure domain and stiffness. The failure domain is the combination of the vertical (N) and horizontal (T) forces at which kit failure is achieved; stiffness is described by the ratio of the force, N or T, applied on the kit hinge and the corresponding displacement. Under cyclic loads, such as those due to wind or earthquake, the mechanical behavior of the kit is described in terms of the displacement accumulated during the application of the load cycles and the change in stiffness.

Servo-hydraulic actuators and displacement transducers: the uniqueness of LPMS

Tests to study the mechanical behavior were carried out in the LPMS Laboratory of the University of Trento, using two servo-hydraulic actuators, to apply forces or displacements on the hinge, and displacement transducers, both contact and wire, to measure the displacements of the precast concrete beam and cage. The qualifying and unique parts of LPMS consist of the bidirectional reaction wall composed of a prestressed reinforced concrete wall with a height of 9.5 m, and a reaction deck with a length of 42 m. The LPMS is ISO 9001:2015 certified.

Preliminary evidence: geometry and EAD

Much of the experimental work was devoted to developing the most effective test protocols to capture the mechanical characteristics of the kit. These test protocols have been discussed with the TAB and EOTA and have now been incorporated as assessment In EAD 200171-00-0103 "welded gabion kits for use in building foundations". At the same time, the optimal geometric characteristics of the kit and, in particular, of the precast concrete beam, and the number and position of the anchor bolts connecting the concrete beam to the gabion base panel were defined.

Definitive evidence: the ETA

A total of 41 tests were performed in the following months, 10 of which were performed under cyclic loading and the remaining under monotonic loading (https://www.ingenio-web.it/articoli/fondazioni-a-secco-per-edifici-in-legno/). In detail, the following were performed:

21 Monotonic tests on dry foundations on rigid floor,
5 Monotonic tests on dry foundation on water mattress,
5 Monotonic tests on the threaded bars of steel hinges,
3 vertical cyclic load tests,
5 Cyclic horizontal symmetrical load tests,
2 Asymmetric horizontal cyclic load tests.

The test results, reported in the ETA, delimited the failure domain with 3 failure mechanisms: punching of the precast concrete beam, shear failure of the hinge threaded bar, and sliding of the kit on the laying surface.

The displacements accumulated during the load cycles were found to be negligible.

Role of pebbles: the Hybrid Structures with Pebbles (StIC) project.

The sustainability of the LSF foundation is closely linked to the possibility of filling the welded mesh cage with reclaimed pebbles near the site area because, in this way, it makes the transport of the foundation from the production site to the site of use more efficient. But if you change quarries, does the same ETA still apply? This is the question being answered by the two-year research and development project StIC: Hybrid Structures with Pebbles, funded by the Caritro Foundation (project no. 2022.0495). Additional tests were carried out during the project using pebbles with different lithology, shape and grain size curve.

Eng. Lucia Simeoni

Lucia Simeoni is a geotechnical engineer and lecturer at the University of Trento. With a PhD in Geotechnical Engineering from the Polytechnic University of Turin, she conducts research on slope stability, geotechnical monitoring and risk management. She is the author of numerous scientific publications, a member of international committees and a lecturer in courses on geotechnics and support works.