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

Job Description

Thesis Subject

The issue of long-term damage to rock masses is of paramount importance for understanding gravitational instability phenomena. In the case of cliffs subjected to both gravitational loading and cyclic stresses induced by weather conditions, we are still far from a quantitative understanding.
Thus, the assessment of the impact of climatic conditions on rock damage remains mostly qualitative.
The thesis work proposed here aims to advance this field by combining:
• in situ measurement of weather conditions,
• numerical simulation of thermo-mechanical coupling under transient conditions,
• application of theoretical subcritical cracking laws. The relationship between these three approaches is as follows.
In situ measurements provide the thermal loads applied to the material. They serve both as a source of input data and as a calibration basis for transient thermal modeling. The calculation of thermo-mechanical coupling then allows for the characterization of spatial and temporal variations in the stress state within the rock mass.

This characterization ultimately enables the identification of the relevant parameters to be incorporated into theoretical models of subcritical damage (cyclic fatigue, subcritical cracking, thermal activation).
ISTerre possesses the necessary experimental resources and expertise in these three areas, which will be leveraged to make significant progress in understanding the long-term damage to rock cliffs.

Required skills:
• Proficiency in heat transfer phenomena and thermo-mechanical coupling
• Experience in thermo-mechanical numerical simulation, particularly using the finite element method
• Proficiency in Python for numerical simulation and data analysis
• Interest in natural erosion processes and their sensitivity to climatic conditions

Your Work Environment

The thesis will be conducted at the ISTerre laboratory.
ISTerre is a Joint Research Unit of the University of Grenoble Alpes, the CNRS, USMB, IRD, and Gustave Eiffel University, located at 1381 Rue de la Piscine, 38400 Saint-Martin-d'Hères, and on the Bourget-du-Lac Science Campus.
It is part of the Grenoble Observatory of Universe Sciences (OSUG) and the PAGE Research Cluster at the University of Grenoble Alpes (UGA). It has a staff of approximately 300 people and an average annual budget of €7 million.

It is organized into 9 research and service teams, with the scientific objective being the physical and chemical study of the Earth, particularly focusing on the interplay between observations of natural objects, experimentation, and the modeling of associated complex processes.

ISTerre also carries out Earth observation missions, hosts and maintains national geophysical instrument networks, as well as a data center.

The thesis will be conducted within the Fault Team.
The affiliated doctoral school will be ED STEP.

Constraints and risks

The doctoral thesis involves fieldwork, sometimes in mountainous terrain, which may (optionally) require the use of rope access techniques and/or work in snowy conditions. Prior experience is preferred but not required. Appropriate training will be provided.

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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