PhD thesis « Fatigue and Progressive cracking of natural rock under cyclical stress and environmental loadings : field experiments » (M/F)

Job Description

Thesis Subject

Understanding the long-term damage of rock masses is a fundamental challenge for predicting and anticipating gravitational instabilities. In particular, rock cliffs subjected to both constant gravitational loading and cyclic environmental forcing represent a critical yet poorly understood system. Despite their societal relevance, the mechanisms governing climate-driven damage accumulation in such systems remain largely unresolved, and current assessments of the impact of climate variability on rock degradation are predominantly qualitative.
This project aims to achieve a quantitative, physics-based understanding of long-term rock damage by establishing a direct link between environmental forcing and subcritical fracture processes. To this end, it proposes an original and strongly interdisciplinary approach combining:
- in situ monitoring of meteorological and thermal conditions at high temporal resolution,
- advanced numerical simulations of transient thermo-mechanical coupling,
- predictive theoretical frameworks for subcritical crack growth and damage evolution.
The central hypothesis of the project is that climate-induced thermal fluctuations generate complex, time-dependent stress fields, which in turn control subcritical crack growth and progressive damage accumulation in rock masses.
The project is structured around a tight integration of observation, modeling, and theory. In situ measurements will provide a unique, high-resolution description of thermal forcing and boundary conditions. These data will serve both as input and calibration benchmarks for transient thermo-mechanical simulations, enabling the reconstruction of spatially and temporally resolved stress fields within rock cliffs. Building on this, the project will identify the key physical parameters governing subcritical damage processes, including cyclic fatigue, stress corrosion, and thermally activated crack growth.
By bridging scales from environmental forcing to micro-mechanical damage processes, the project will deliver a new predictive framework for climate-driven rock degradation.
ISTerre provides a uniquely suitable environment for this project, with world-class expertise in field instrumentation, numerical modelling, and rock mechanics. This combination will enable a decisive step forward in the quantitative understanding of long-term rock damage and its sensitivity to climate variability.
Required skills:
- Strong background in heat transfer and thermo-mechanical coupling
- Proven experience in numerical modelling, particularly finite element methods
- Proficiency in Python for numerical simulation and data analysis
- Interest in geophysical processes, especially erosion and climate–rock interactions
- Signal processing, mechanics, material sciences.
- An interest in numerical modeling and/or rock mechanics is crucial.
- An interest in field experiments, including mountainous environments, will be highly appreciated.
- A valid driving license is mandatory.
- A good level in spoken and written english is mandatory (B2).
The candidate will hold a Master's degree or Engineering degree in mechanics, physics or geophysics.

Your Work Environment

The candidate will work at the ISTerre research laboratory, a joint research unit (UMR) comprising approximately 330 staff members, and is part of the Observatory of Universe Sciences (OSU) at the University of Grenoble Alpes (UGA), which is responsible for numerous national observation services.
The thesis will be conducted within the “Mechanics of Faults and Instabilities” team, which consists of approximately 30 researchers, faculty members, postdoctoral researchers, and doctoral students.
The thesis work will involve collaboration with the team led by MH Derron at the University of Lausanne, which has extensive expertise in the field of thermal imaging (infrared imaging of cliffs).
Supervizing team :
E. Larose : PhD Director
D. Amitrano : PhD co-director
L. Baillet (expert ISterre), M-H Derron (UNIL)
The affiliated doctoral school will be STEP.

Constraints and risks

The PhD thesis includes field work, sometimes in mountainous environment with (optional) rope access and/or snow conditions. Previous experiences will be appreciated, though not mandatory. Proper training will be guaranteed.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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