Parallel Session B-8: Material behaviour - Chair: Matteo Ciantia

Engineer barrier system will be built using blocks of compacted bentonites or combination of high density clay pellets mixtures and blocks of compacted bentonites. Most of the research has been mainly focused on compacted bentonites looking at several factors on their swelling pressure capacity. However, investigations to study the behavior of high density pelletized clay mixtures relatively less attention has been placed in this type of material. The aim of this research is to gain a better understanding of the swelling pressure behavior of clayed materials intended as potential barriers materials for the safe isolation of the HLW/SNF.

An innovative equipment, CYC-DOSS, is developed at the TU Delft to investigate the response of soft soils from the deltaic areas of the Netherlands to seismic events caused by energy technologies. The new device is a multidirectional shear simulator that overcomes the limitations of traditional devices by abandoning a homogenous stress-strain state and monitoring the response with local sensors, capable of reproducing the full acceleration time history of seismic events. The apparatus can apply a variety of multidirectional cyclic loading patterns, providing crucial information to develop and calibrate advanced constitutive models for soft soils.

The size and type of suspended particles, as well as their interaction with the solvent, are key factors in dewatering and consolidation processes. Those systems may undergo either a slow sedimentation or fast sedimentation depending on the diffusive forces and advective forces that are predominant. In this presentation, we will show that the behaviour of this suspensions can be numerically modelled using advective diffusion equation. We will try to predict the sedimentation process of many mineral clay suspensions of different sizes and then evaluate the accuracy of those predictions based on the experimental collected data using the NMR method

Hydrogen is considered as a promising energy carrier but its massive storage is still a major issue to be solved. Underground storage in salt cavern has already been used for decades to store hydrocarbons and need to be adapted to the storage of hydrogen. Our studies aim at characterizing the development of damage networks in halite through in situ X ray microcomputed tomography analysis, digital volume correlation and damage quantification. Using a triaxial device adapted to in situ XR µCT tests, we study the micro mechanisms involved and the deformation of synthetic halite with different water content under various confining

1. Geothermal pavements improved thermo-mechanical performance. 2. Point scale experimental study on influence of microbially induced calcium carbonate (CaCO3) precipitation (MICP) on thermal conductivity. 3. Changes in thermal conductivity of treated soils with increasing strain (triaxial testing).

This abstract is about creating a model for understanding the factors affecting the threshold FC and to model the maximum and minimum void ratios of the carbonate sand-silt mixtures using the DEM.