Irini Djeran-Maigre

Institut National des Sciences Appliquées de Lyon | INSA Lyon · Department of Civil Engineering and Urban Planning (GCU)

Mixtures of crushed excavated COx claystone and bentonite are considered as a potential backfill solution for the French disposal concept of radioactive waste. In the present work, the hydro-mechanical behaviour of claystone/sodium bentonite mixtures was experimentally investigated for various bentonite contents (≤40% in total mass) and densities....

Natural fibers investigated in this study are mainly waste from agro industry. The importance of natural fibers in building composites is increasing, as they partially replace nonrenewable natural resources acting as reinforcement in composite materials such as concrete, mortar and earth bricks. Their recycling requires a detailed analysis of the p...

Reuse of dredged sediments is an effective approach to waste management. This study focuses on the reuse of Usumacinta River dredged sediments in fired bricks. Physico-chemical characteristics of sediments were investigated for their reuse. The grain size of sediments shows that Usumacinta sediments have a sandy texture with low organic matter. The...

A feasibility study on Usumacinta River sediment-based bricks for resilient housing adapted to both climate change and seismic risks is performed on laterally loaded reduced-scale walls. Mortar formulations with different volume ratios of lime and sand (2/1, 1/2, 1/4, 1/6) are prepared while different types of sediment-based bricks are thoroughly i...

Purpose Transportation is a key factor for economic growth and poverty reduction because it improves access to services and opportunities for rural communities. Unpaved roads, however, still represent 80% of the global road network. The state of Tabasco, Mexico, is not an exception. Materials and methods Geotechnical identifications of raw and lim...

A numerical model able to simulate the grain breakage with the discrete element method, using the "Non-Smooth Contact Dynamics" is presented. The model reproduces 3D grains having complex shapes and is tested in single grain and in oedometric compressions. Numerical simulations are then carried out to evaluate the different energies active during b...

Dredged sediments from ports and rivers are treated as waste material. The disposal of waste sediments has environmental concerns and requires financial resources. Dredged sediments reuse in building material such as adobe bricks can provide an alternate solution to valorize and handle this waste material. Adobe bricks are eco-friendly construction...

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percen...

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percen...

Earth bricks are a traditional eco-friendly construction material. In this study, harbor-dredged sediments were used along with hemp shiv to develop a brick manufacturing procedure and compaction techniques to produce durable earth bricks for the valorization of waste hemp shiv and dredged sediments. Prismatic specimens of size 4 × 4 × 16 cm3 were...

The palm oil industry is the leading source of palm oil waste fibers. The disposal of palm oil waste fibers by burning or dumping causes environmental issues such as the emission of CO2 and a diminution in soil fertility. Natural fiber reuse in construction materials such as concrete, mortar and adobe bricks as reinforcement provides a possible eco...

Mixture of excavated Callovo-Oxfordian (COx) argillite and MX80 bentonite has been proposed as potential sealing material for the French deep geological disposal facility of radioactive waste. The mixtures hydro-mechanical behaviour was studied in order to assess their response on design requirements. At the as-compacted state, soil fabric analysed...

A pelletized solution composed of COx argillite and MX80 bentonite is examined as backfill for the deep geological disposal of radioactive waste (Cigeo project). The implementation is studied in terms of installation and hydration conditions as well as their influence on the hydro-mechanical behavior of the mixture. In the beginning, the optimum gr...

This paper presents an efficient hybrid asynchronous three-dimensional (3D) perfectly matched layer (PML) for modeling unbounded domains. The proposed unsplit explicit or implicit 3D PML formulation is implemented in the framework of a heterogeneous asynchronous time integrator. It is fully versatile in terms of time integrators and time step sizes...

A numerical model able to simulate the grain breakage with the discrete element method, using the “Non-Smooth Contact Dynamics” is presented. The model reproduces 3D grains having complex shapes and is tested in single grain and in oedometric compressions. Numerical simulations are then carried out to evaluate the different energies active during b...

A poroplastic damage model is proposed for modeling the mechanical behaviour of deep argillaceous rocks. A second order tensor is introduced to characterize damage state. We presented here a numerical algorithm. The parameters are determined from drained triaxial compression test. Comparison between numerical simulations and experimental data are p...

Pelletized material made of COx argillite/MX80 bentonite mixture is one of the possible options for the backfill of radioactive waste disposal. Numerical simulations are conducted to optimize the granulometry maximizing the emplaced density of a granular material.. An experimental work is conducted to evaluate the hydromechanical response of variou...

This paper presents a benchmark for three-dimensional explicit asynchronous absorbing layers for modeling unbounded domains through a standard displacement-based finite element method: Three-dimensional Perfectly Matched Layers (PML) is compared to recently proposed Absorbing Layers with Increasing Damping (ALID) based on Rayleigh and Kosloff dampi...

The French National Radioactive Waste Management Agency (Andra) is in charge of the study on the feasibility of disposal for high level and intermediate level-long lived radioactive waste (Cigéo project) in a deep Callovo-Oxfordian (COx) claystone formation. The facility’s safe operation indicates the progressive closure by installing seals in key-...

Coarse granular materials exhibit important grain breakage in civil engineering structures, making it more complicated to predict the settlement and collapse of structures. A three-dimensional numerical model is presented using the discrete element method (Non-Smooth Contact Dynamics method). Polyhedral grains are generated, divided into tetrahedra...

This paper presents a novel approach for modeling infinite media, called Hybrid (different time integrators) Asynchronous (different time steps) Kosloff Absorbing Layers with Increasing Damping (HA-Kosloff ALID). By using strong forms of wave propagation in Kosloff media, its design equation is derived as well as optimal conditions between physical...

Co-simulation strategies using both Abaqus/Explicit and Abaqus/Implicit are investigated for analysing wave propagation in two-dimensional unbounded soil domain. The co-simulation is based on the coupling GC method, allowing for coupling different finite element codes with different time integrators and time-scales depending on the partitions of th...

Co-simulation strategies using both Abaqus/Explicit and Abaqus/Implicit are investigated for analysing wave barrier in 2D unbounded soil domain. The Co-simulation is based on the coupling GC method, allowing for coupling different finite element codes with different time integrators and time-scales depending on the partitions of the domain. Absorbi...

Foaming agents are frequently used to dig tunnels in soft ground. These additives are often considered to be biodegradable. However, the soil fine material of excavated treated soils is generally classified as waste, stored, and not used again. The foaming agent addition affects the hydromechanical property of the soil, and the resulting evolution...

Grain breakage in rockfill in civil engineering structures is the major cause responsible for settlement and collapse. It is inherently due to large grain size and angular shape of the grains. To model these features, a three-dimensional discrete element model of a breakable grain is presented hereafter. The model is able to reproduce grain breakag...

A three-dimensional grain model based on the concept of particles assembly using cohesive bonds is presented. A script is developed to generate polyhedral grains, by assembling tetrahedral particles using cohesive bonds. A series of single grain crushing simulations is performed, and the effect of the intra-granular cohesion on the grain’s strength...

The presented mathematical textbook is devoted to presentation of several topics of higher mathematics that are either not taught in the majority of technical universities, or delivered in the form of very short courses. To fill in the gap, the authors presented a textbook that covers such mathematical topics as elements of topological, metric and...

A breakable grain model is presented, using the concept of particles assembly. Grains of polyhedral shapes are generated, formed by joining together tetrahedral subgrains using cohesive bonds. Single grain crushing simulations are performed for multiple values of the intra-granular cohesion to study the effect on the grain’s strength. The same effe...

Perfectly Matched Layer (PML) is recognized as a very effective tool for modeling unbounded domains. Nonetheless, the computation time required by the PML may be large, especially when an explicit time integration scheme is adopted for dealing with the wave propagation problem both in the domain of interest and in the PML medium. In this paper, it...

An experimental program is carried out to investigate the swelling properties of Na activated Ca-bentonite submitted to prehydration and polymer adding, using Free Swell Index (FSI). Three Na activated Ca-bentonite are used: S, T and V. Various concentrations (0.5, 1, 1.5 and 2%) of two polyelectrolyte polymers are mixed with bentonites to underlin...

L’analyse de l’impact du traitement par agents moussant, sur les sols excavés est étudiée. Les mécanismes de dégradation des effets du traitement sont analysés et quantifiés. Des essais géotechnique, hydraulique et rhéologique sont utilisés pour caractériser l’évolution des propriétés des sols traités. L’état émulsionné des tensio-actifs est l’élém...

This paper investigates the role of force chains in granular materials under both quasi-static biaxial loading and dynamic impact loading conditions. This study is mainly interested in investigating the role of force chains on the global mechanical responses of samples as well as on the microstructure of granular materials. For this purpose, discre...

An experimental program is carried out to investigate the long term hydro-mechanical behavior correlated with chemical one of compacted soils with low concentration of Ca-bentonite and Ca-bentonite polymer mixture. The effect of prehydration on the hydraulic performance is compared to the polymer adding effect. All specimens are submitted to synthe...

This paper attempts to elucidate the mechanism of failure in rate-independent granular materials using the discrete element method. For this purpose, the dynamic response of dense and loose specimens has been simulated over drained and undrained loading paths. Then, this paper revisits the relation between the occurrence of an outburst in kinetic e...

Bentonite is used for landfill application because of its high sealing ability. Following the swelling phenomenon the water reacts with the bentonite and expands the solid particles. The voids are filled and this reduces permeability of the soil. However, the drawback is the long time needed to assess the hydraulic performance, whereas the engineer...

This study focuses on the mesoscale mechanism of the two dimensional granular materials, involving 2 structures: the force-chains and the grains cycles. These two structures are the essential elements contribute to the behavior of the specimen and they share a very close relation. By using the discrete element method, a dense 2D specimen of a spher...

Various techniques are proposed for reproducing the elastic wave propagation in an unbounded medium such as the infinite elements, the absorbing boundary conditions or the perfect matched layers. Here, a simplified approach is adopted by considering absorbing layers characterized by the viscous Rayleigh matrix as studied by Semblat et al [1] and Ra...

Variant techniques are proposed for reproducing the elastic wave propagation in an unbounded medium such as the infinite elements, the absorbing boundary conditions or the perfect matched layers. Here, a simplified approach is adopted by considering absorbing layers characterized by the viscous Rayleigh matrix as studied by Semblat et al. [16] and...

Development of the underground construction system in urban areas in Vietnam, such as Hanoi capital and Ho Chi Minh city, plays an important role to improve the public infrastructures. As most of the tunnels driven in urban areas using mechanized tunnelling method, segmental linings will be utilized in this project. One of the most important aspect...

The application of the mechanized tunnelling has been extended in recent years. There are at present different approaches that are used in the design of segmental tunnel linings supported in mechanized tunnels. Even though segmental lining is utilized for mechanized tunnels, its behaviour is still quite unclear under in situ stress and there is a l...

A numerical investigation on the performance of wave barrier and a developed optimization design method for wave barrier are presented. Firstly, a two-dimensional (2D) numerical model is built in ABAQUS and the results are verified by previous publications. A comparative study of the 2D model and three-dimensional (3D) model is also carried out. Th...

The development of transportation in large cities requires the construction of twin tunnels located at shallow depth. As far as twin tunnels excavated in parallel are concerned, most of the cases reported in literature focused on considering the effect of the ground condition, tunnel size, depth, surface loads, the relative position between two tun...

The field of application of mechanized tunnelling has been extended in recent years. Segmental linings are usually utilized in these tunnels. So far no single effective calculation method exists for segmental lining design. Analyses of segmental tunnel lining using analytical method by Einstein & Schwartz, the elastic equation method, a numerical a...

A mathematical model is worked out for analyzing propagation ability and the specific energy of horizontally polarized shear surface waves (SH-waves) in multilayered plates. All the layers are assumed to have monoclinic symmetry. Different types of boundary conditions imposed on the outer surfaces of plates are considered. Analytic solutions for on...

This paper proposes a numerical approach to the Hyperstatic Reaction Method (HRM) for the analysis of segmental tunnel linings. The influence of segmental joints has been considered directly using a fixity ratio that is determined on the basis of the rotational stiffness. The parameters necessary for the calculation are presented. A specific implem...

Tunnel excavation is a three-dimensional (3D) problem. However, despite recent advances in computing resources, 3D models are still computationally inefficient and two-dimensional (2D) simulations are therefore often used. Modelling the tunnelling process in a 2D plane strain analysis requires a specific approach that allows a 3D tunnelling effect...

This paper aims to study the hydromechanical behaviour and the clay polymer interaction of amended Ca-bentonite. Specimens were formed by mixing Ca-bentonite with two soluble polyelectrolyte polymer powders. Some important parameters are studied: swelling, water adsorption and hydraulic performance for landfill applications. Tests are performed wit...

A novel approach developed by the authors to predict the behaviour of unsaturated soils is discussed in this paper to investigate the effect of rainfall event on the stability of soil slopes. Heavy rainfall is one of the main factors that induce shallow landslides. This type of landslide usually takes place in partial saturated slopes. Numerical mo...

One of the most important factors in the design of a segmental tunnel lining is the influence of the segmental joints on its overall behaviour. In this study, a reduction factor has been applied to the bending rigidity of the segmental tunnel lining. An improved numerical hyperstatic reaction method (HRM) approach, which is developed on the basis o...

The development of transportation in large cities requires the construction of twin tunnels located at shallow depth. As far as twin tunnels excavated in parallel are concerned, most of the cases reported in literature focused on considering the effect of the ground condition, tunnel size, depth, surface loads, the relative position between two tun...

The main purpose of this study was to provide a three-dimensional numerical model, which would allow the tunnel lining behaviour and the displacement field surrounding the tunnel to be evaluated. Most of the processes that occur during mechanized excavation have been simulated in this model. The influence of the lining joint pattern, including segm...

The main purpose of this study was to provide a three-dimensional numerical model which would allow to show the influence of the constitutive model of the ground on the tunnel lining behaviour and displacement field surrounding the tunnel. Most of the processes that occur during mechanized excavation have been simulated in this model. Besides the w...

This paper aims to study the hydromechanical behaviour and the clay polymer interaction of amended Cabentonite.Samples were formed by mixing of Ca-bentonite with two soluble polyelectrolyte polymer powders.Some important parameters are studied: swelling, water adsorption and hydraulic performance for landfill andearthwork applications. Tests are pe...

A numerical investigation on the effectiveness of wave barriers in reducing ground vibrations caused by explosion is presented. Firstly, a Two-Dimensional (2D) model is built in ABAQUS and the reliability that ABAQUS produces accurate results is verified. Then, an extensive parametric study is conducted to examine the effect of various parameters o...

Understanding the response of partially saturated soils under different loads is important for the design and construction of economical and safe geotechnical engineering structures. This paper presents a coupled elastoplastic constitutive model for predicting the hydraulic and stress–strain–strength behaviour of unsaturated soils. The model propos...

The development of transportation in large cities requires the construction of tunnels. In many tunneling projects surface settlements have been observed. Most of the cases reported in the literature focus on considering the effect of ground conditions, tunnel size, depth, surface loads, and construction process on the ground surface settlement. Ho...