The role of natural thermal cycles on a limestone cliff mechanical behaviour

Muriel Gasc-Barbier (1) , Véronique Merrien-Soukatchoff (2, 3) , Didier Virely (4)

1 GeoCoD - Géomatériaux et géomécanique : couplages et dynamique en géotechnique
2 GeF - Laboratoire Géomatique et foncier
3 CNAM - Conservatoire National des Arts et Métiers [CNAM]
4 Cerema Direction Sud-Ouest - Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Direction Sud-Ouest

Rock instabilities can represent major risks for local populations depending on their geographical location. Even if different mechanisms are known to trigger rockfalls such as precipitation, seismic activity and freezing, many rockfalls occur during periods when such trigger mechanisms are absent. Some recent studies have pointed out the role of thermal cycling in crack initiation or propagation. Here we use data from nearly five years of field monitoring of a French limestone cliff. Evolution of the aperture of joints were followed as well as displacements and temperature deep in the rock mass. We show that seasonal thermal variation affects the rock at depths of up to 6 m and subcritical cracking can probably appear even at this depth.

Mots clés: Thermo-mechanical damage; Thermal cycles; Limestone; In situ monitoring; Climate impact

Domaines: Risques; Géologie appliquée

Muriel Gasc-Barbier, Véronique Merrien-Soukatchoff, Didier Virely. The role of natural thermal cycles on a limestone cliff mechanical behaviour. Engineering Geology, 2021, 293, pp.106293. ⟨10.1016/j.enggeo.2021.106293⟩. ⟨hal-03319850⟩