RO2 : Vulnerability, reliability and resilience of structures and networks

Activities

The objective of this research operation is to assess the vulnerability, reliability and resilience of civil engineering structures within their environment. By looking at these structures throughout their life cycle, from their design to sometimes thousands of years, all the risks that could alter their durability and serviceability can be taken into account and reduced. The materials concerned (whether soils or those constituting the structures such as concrete, steel, masonry, wood, etc.) have complex behaviours to understand from a mechanical, physical or chemical point of view. In order to address this vulnerability issue, experimental approaches and numerical developments are proposed in a complementary manner. All spatial scales are investigated in order to obtain a complete vision of the problem.

• At the microscopic scale and below, experimental studies on the physico-chemical properties of materials are carried out. In addition, molecular simulations are used to predict the multi-physical behaviour (thermal, hydric and mechanical) of the different phases of construction materials. It is at this scale that shrinkage and creep mechanisms occur. These studies then inform the higher scales by developing analytical and numerical homogenisation tools in a multi-scale and multi-physics understanding approach.
• At the mesoscopic scale, calculation codes (which can combine finite and discrete elements) are developed to model the non-linearities that occur in materials subjected to chemical, thermal, hydric and/or mechanical stresses. Characterisation tests and 2D, 3D and 4D field measurements are used at this scale to inform and improve the modelling. The heterogeneous nature of the materials considered is also investigated by analysing the meso-structure and its influence on the variability of behaviour.
• At the macroscopic scale, the response of structures and equipment is studied. The strong interaction with the ground, which can play an important role in the static or dynamic behaviour, or with other structures is an important issue for the design of a structure in its environment. In this case too, the experimental facilities are used to carry out tests on the scale of the structure, among others using hybrid approaches and several field measurement techniques.

Research actions developed

• Direct and inverse numerical simulations,
• Massive data assimilation and machine learning,
• Construction of hybrid twins (physical and statistical meta-models),
• Model-based building design.