Committee:
     PRESIDENT: NAVARRO GAMIR, VICENTE
     SECRETARI: RAMON TARRAGONA, ANNA
     VOCAL: PINTADO LLURBA, XAVIER CESAR
Thesis abstract: Unsaturated soils are particular instances of porous materials, which are characterized by a solid skeleton and a number of fluids that can move through the skeleton. At the microscale, a porous material is made of interacting entities of various dimensions (3D phases, 2D interfaces, 1D common lines, 0D common points), which contain various species (mineral, water, air, …). If representative volume elements (REV) can be defined, averaging yields a set of macroscale interacting continua, which can be modeled using mixture theory. After averaging, the microscale geometric features of the entities and the microscale distributions of thermodynamic properties within the entities are lost. In order to recover part of this information, macroscale geometric variables (e.g. volume, area, length or number of points of each entity in the REV) and macroscale density variables (e.g. mass of each species in each entity in the REV) are defined. Additional macroscale variables can be defined in order to characterize the anisotropy of the porous material (e.g. structure tensors).The state of a porous material is assumed to be given by the deformation of the solid skeleton, the measure (volume, area, length, number of points) of each microscale entity in the REV, the mass of each species in each microscale entity in the REV, the temperature and a set of internal variables. The number of state variables can be significantly reduced by assuming that the evolution of the porous material is along local equilibrium states. These states are such that, for prescribed values of the strain tensor of the solid skeleton, the total mass of each species per unit reference volume, the temperature and the internal variables, the measure of each microscale entity in the REV and of the mass of each species in each microscale entity in the REV take unique values, such that the total free energy per unit reference volume is minimum. As a result, the state of a porous material is given by the strain tensor of the solid skeleton, the total mass of each species per unit reference volume, the temperature and the internal variables. The constitutive model of a porous material is derived using the framework of thermodynamics with internal variables, in which the porous material is considered to be an open thermodynamic system. The state equations are derived from the free energy and the evolution equations of the internal variables are derived from the dissipation or a dissipation potential. For unsaturated soils, additional simplifying assumptions are made: (1) small strains of the solid skeleton; (2) isothermal atmospheric conditions; (3) three species: solid mineral, water and gas; and (4) elastoplastic response of the deformation of the solid skeleton and of the water mass content.In some soils short-range interaction forces bond water to the solid skeleton. Vicinal water is bond to the solid skeleton, whereas free water is not. The behavior of free water is as if it were outside the soil, so that microscale pressure distributions are uniform (neglecting gravity), so that chemical potentials and temperature allow to define a macroscale pressure. In contrast, the behavior of vicinal water depends on the interaction forces, so that microscale pressure distributions are not uniform. The behavior of a soil is assumed to be given by three different regimes: (1) saturated (fixed vicinal water, variable free water, no gas phase); (2) capillary (fixed vicinal water, variable free water, gas phase), with an hysteretic water retention curve; and (3) dry (variable vicinal water, no free water, gas phase). At each of these regimes a different constitutive model for the soil is used. Generic examples of these models are given: elastoplastic for the saturated regime, elastoplastic with water content hysteresis for the capillary regime and elastoplastic for the dry regime.

Committee:
     PRESIDENT: LIZCANO, ARCESIO
     SECRETARI: OLIVELLA PASTALLE, SEBASTIAN
     VOCAL: CUOMO, SABATINO
Thesis abstract: The Material Point Method (MPM) is presented as an advanced numerical method used to simulate geotechnical problems subjected to large deformations and soil-structure interaction problems, such as landslides, penetration issues, and collapse of geotechnical structures. Its main advantage is the ability to simulate large movements without the mesh-related problems typical of the standard Finite Element Method (FEM).Simulating different material states and external conditions is a challenging aspect in geotechnical engineering. This process requires a detailed analysis of how to address phenomena such as rainfall and water flow through the soil. Additionally, it is crucial to incorporate material constitutive relationships to properly replicate or predict stress-strain behavior.The modelling of unsaturated soils is necessary in various fields, especially in geotechnical works employing compacted materials such as embankments, dams, fills, and natural slopes. The study and analysis of these soils requires modelling the entire process of the work, from its construction, if applicable, to post-failure behavior.Until now, simulating the unsaturated state of materials has mainly relied on FEM, assuming small deformations at a theoretical level. This involves developing coupled mechanical and hydraulic constitutive models and utilizing advanced numerical tools. This Thesis presents advancements in modelling unsaturated soils in large deformation problems through the development of the MPM. The formulation of a single-point, multi-phases has been used, showing its potential for improving the accuracy and reliability of geotechnical simulations involving large deformations.Firstly, the developments for simulating boundary conditions for unsaturated soils (imposed flow and seepage condition) are presented. These conditions are complex, particularly since the boundary where they are applied is not fixed and must be determined during the calculations. Validation of these conditions is consistently performed using a soil column subjected to infiltration flow. The results are compared with those obtained from a widely used finite element code, giving similar results.Next, for the first time, the modelling of wetting collapse in MPM is proposed. A constitutive model is implemented to capture the key characteristics of unsaturated material behavior. This model is based on critical state theory and employs two alternative formulations, depending on whether Bishop's stress or net stress is used, along with suction. Validation is conducted through conventional laboratory tests.The loss of volume due to wetting is analysed, a characteristic associated with unsaturated soils with an open structure. The loss of suction in the material leads to a loss of strength and, consequently, the possibility of failure. This is illustrated by a physical test conducted in a centrifuge on a slope subjected to a rising water table from the base, which results in the evolution of the saturation front, collapse-induced deformations, and ultimately a landslide when critical saturation conditions are reached.Finally, one of the objectives of this Thesis is to model the entire process of a geotechnical project. To achieve this, a numerical scheme was implemented to simulate construction stages, representing a significant advancement in the application of the MPM for analysing material behavior during the pre-failure stage.Modelling of the construction process is crucial because it not only represents the construction process and the displacements occurring during it, but also establishes the initial state of the structure for subsequent analysis stages. The proposed scheme effectively captures deformations and failure processes during construction, unlike conventional methods based on Eulerian formulations, which cannot accommodate large material displacements during construction

Committee:
     PRESIDENT: PRAT CATALAN, PERE
     SECRETARI: SEGURA SERRA, JOSE MARIA
     VOCAL: XOTTA, GIOVANNA
Thesis abstract: To address the impacts of climate change, several measures have been suggested among which utilizing renewable energy sources such as geothermal energy and implementing technologies such as hydrogen storage or CCUS. Some of these solutions imply the injection of fluids into fractured rock masses (e.g. depleted O&G reservoirs) with the subsequent change in local stress conditions. This alteration may lead to the initiation of micro-seismic events by reactivating existing faults or the generation of new fractures, with the risk of ultimately establishing pathways for fluid leakage. Additionally, depleted reservoirs contain multiphase and multicomponent fluids that could react chemically with the new injection fluids. Therefore, the accurate prediction of operation conditions demands advanced geomechanical software capable of evaluating the viability and safety of potential extraction or storage locations. In this context, the main objective of this thesis is to develop a thermo-hydro-mechanical multiphase model in fractured porous medium with the Finite Element Method using zero-thickness interface elements to model discrete discontinuities. The main assumptions of the model are: the small strain theory, the system composition with two fluid phases (liquid and gas), two species (water and dry gas) and one solid phase. The gas phase follows the ideal gas law and the liquid phase evaporation is considered. The main variables are: displacements, phase pressures and temperature. The formulation takes into account: the equilibrium equation, the mass balance equation of the water species, the mass balance equation of the gas species and the balance of energy. The formulation of the discontinuities considers similar assumptions as the porous medium and takes into account a reduction factor of the water retention curve parameters based on the mechanical opening of the fracture. The model has been implemented and validated with academic verification examples in a FE code.However, some limitations were observed related to the time integration scheme, the treatment of storage terms of the governing equations and the mass flow. This issues have motivated the following new developments: new mass-conservative approach for diffusion equations using FE formulations, a new physically-based exponential model which considers the pore size or aperture distribution in case of the porous medium or discontinuities, respectively, and a new damage-frictional law which properly models discontinuity closure.

Committee:
     PRESIDENT: SALOMONI, VALENTINA
     SECRETARI: PRAT CATALAN, PERE
     VOCAL: LIAUDAT, JOAQUÍN
     VOCAL: CIANCIO, DANIELA
     VOCAL: MAROTTI DE SCIARRA, FRANCESCO
Thesis abstract: When concrete is subject to an environment characterised by a high humidity index and rich in sulphate ions, a concrete degradation process may be initiated due to External Sulphate Attack (ESA). The sulphate penetrating into the concrete activates a series of chemical reactions that lead to the formation of secondary ettringite, which may cause non-uniform volumetric expansions that may in turn generate cracking and ultimately culminate in the disintegration of the sample. Because the cracking may in turn facilitate sulphate penetration, ESA may be considered a coupled chemical-mechanical problem. In this study, the numerical analysis of ESA is conducted using the Finite Element Method by considering the specimen at the meso-level composed of larger aggregates embedded in a mortar matrix. Standard continuum finite elements are used to discretise the aggregates and the mortar. Zero-thickness interface elements are inserted along all the aggregate-mortar and selected mortar-mortar contacts to represent potential cracks. The diffusion-reaction of sulphate ions (chemical problem) is formulated following Tixier and Mobasher (2003) and Idiart et al. (2011b). Regarding the mechanical problem, the continuum elements are considered linear elastic, while the interface elements behave according to an elasto-plastic law incorporating concepts of fracture mechanics which was initially developed by Carol et al. (1997) and later extended for 3D analysis by Caballero et al. (2006).The first part of this thesis deals with the verification and use of DRAC5, a completely parallelised version of the in-house code developed within the materials mechanics group (MECMAT) of the Universitat Politècnica de Catalunya (UPC) which now incorporates MPI and PETSC libraries as well as HDF5 i/o files. This new version of the code, which is used to solve both the mechanical problem and the chemical problem through a staggered scheme, has allowed the analysis of new and more challenging 3D studies, producing realistic results that reflect the 'onion peeling' cracking pattern, similar to what has been observed in the laboratory and in previously studied 2D cases (Idiart, 2009). The second part of the thesis, deals with the development of new numerical solving techniques applicable to this type of mesh. In particular, a solution technique based on substructuring and the Schur complement is applied to the analysis of specimens comprising elements of the continuum exhibiting linear elastic behaviour and interface elements characterised by non-linear (elasto-plastic) behaviour. This new technique, which reduces substantially the number of degrees of freedom that need to be considered during the iterative process, has been preliminarily implemented in DRAC4, a simpler series version of the code, and is tested showing great advantages in terms of solution time for a range of 2D application examples. The development of a new formulation using rigid-plastic interfaces is also initiated. This formulation uses relative degrees of freedom at each pair of interface nodes, and leads to the resolution of a Linear Complementarity Problem. This development allows a further reduction in the degrees of freedom of the problem by only considering the nodes of the interface elements involved in the fracture process.

Committee:
     PRESIDENT: SAWYER, AUDREY
     SECRETARI: FERNANDEZ GARCIA, DANIEL
     VOCAL NO PRESENCIAL: PALTAN LOPEZ, HOMERO
Thesis abstract: Sustainable groundwater management in rural areas presents multifaceted challenges stemming from hydrogeological complexities, socio-economic disparities, and governance issues. This thesis aims to provide quantitative tools for addressing some of the groundwater access problems in rural areas of low- and middle-income countries by promoting an interdisciplinary approach and the understanding of the expertise of each discipline. The first part of the thesis focuses on developing a comprehensive methodology to assess individual user risk of groundwater shortage. After a preliminary multifactorial analysis incorporating a range of variables from technical to societal, it was found that most of the overall risk of water shortage for an individual household could be attributed to three factors: Proximity, specified as the distance to the closest supply well. Availability of good quality water in the wells, and Sustainability. The factors are mapped onto indicators in the range of [0 - 1] and then represented in a Geographical Information System based on the partition of the entire spatial domain. The three indicators are then combined in a final index based on the product of the three factors, thus mapping time-dependent overall risk and allowing the assessment of temporal risk-evolution scenarios. The methodology is applied to Kwale County, Kenya, where community handpumps and groundwater points comprise the main water supply system. Apart from mapping the present situation, the methodology is also used to assess the impact on hypothetical scenarios. The second part of the thesis extends the analysis to four Eastern African countries, as an attempt to address the complexity and heterogeneity that characterise the human-groundwater interaction in rural water supply systems, we propose a multivariate approach that combines many different variables, such as water point functionality and groundwater quality characteristics, social and economic parameters, such as water point maintenance, finance, and governance system. The combination of variables of very different types and ranges of values is better suited using Multiple Factor Analysis (MFA) as a way to determine formally the main variables that affect water access and the relationship amongst them. The methodology was applied in four different countries of Eastern Africa supplied mainly with hand-pumps. The analysis was performed on datasets collected during a waterpoint census by the UPGro "Hidden Crises" and "Grow for Good" Projects from Kenya, Uganda, Malawi, and Ethiopia. The results of the analysis show the existence of common trends, indicating that water access in Eastern African rural areas can be described mainly by three main components: one representing the hydrogeological environment, a second comprising water point management agreements, and a third component linked to the sustainable functionality of hand-pumps. Finally, the thesis explores into household water usage patterns and the impact of groundwater salinity on (ground)water source selection. A mixed-methods approach combining household surveys and physicochemical analysis of groundwater was employed across Kwale County during the dry season. Co-occurrence matrices were used to analyse usage patterns, while logistic regression models were used to understand the influence of salinity, demographic and socio-economic factors on water source preferences. Despite limited changes in drinking water sources between wet and dry seasons, significant shifts occur in non-drinking water uses, demonstrating the community's adaptability in utilizing available water sources. Factors such as taste, safety, and proximity play significant roles in households' decisions regarding their main drinking water source. Moreover, the study highlights the significant impact of groundwater salinity levels on usage patterns, identifying threshold salinity levels beyond which households are less likely to choose certain water sources.

Committee:
     PRESIDENT: ZHU, HONGHU
     SECRETARI: MOYA SANCHEZ, JOSE
     VOCAL: ZHANG, WENGANG
     VOCAL: ZHONG, QIMING
     VOCAL NO PRESENCIAL: ABANCÓ MARTÍNEZ DE ARENZANA, CLÀUDIA
Thesis abstract: This thesis focuses on the evaluation of shallow landslide susceptibility in mountainous areas induced by rainfall or seismic events. The primary aim is to efficiently assess regional-scale landslide susceptibility based on physical modelling within a probabilistic framework while accounting for uncertainties arising from complex geological conditions and challenges related to data collection. The study proposes an innovative framework for probabilistic landslide susceptibility assessment by introducing the first-order reliability method (FORM) in the platform of geographic information system (GIS), called “"GIS-FORM”". This method effectively addresses the challenge of considering uncertainty in geotechnical parameters methods at the regional scale. In response to the challenge of inefficient computation and low prediction accuracy in regional-scale shallow landslide susceptibility assessment caused by transient rainfall-induced, a simplified instantaneous rainfall infiltration model was proposed based on integrating the GIS-FORM method. The model simulates the variation of the wetting front depth due to the vertical infiltration of rainfall and surface run-off. Subsequently, a general software program was developed for Windows platforms. The results show that the coefficient of variation (COV) of random parameters, statistical correlation, and non-normal distribution have a significant impact on the landslide probability assessment. A rapid assessment framework for the probabilistic susceptibility evaluation of shallow landslides at the regional scale is proposed by integrating the “code "Fast Shallow Landslide Assessment Model" (FSLAM) and GIS-FORM. The study reveals that hydrological conditions can significantly influence the spatial distribution of landslides, particularly under the combined impacts of antecedent rainfall and event rainfall. The extent of the high susceptibility area is observed to increase considerably when the event rainfall is between 77 and 107 mm. To further improve the accuracy of susceptibility assessments, this study proposes an innovative clustering method by utilising image processing techniques. This approach effectively simplifies the raster outcome and markedly enhances the prediction accuracy of susceptibility assessment as well.

Committee:
     PRESIDENT: BROWN, MICHAEL JOHN
     SECRETARI: ALONSO PEREZ DE AGREDA, EDUARDO
     VOCAL: GONZALEZ TEJADA, IGNACIO
Thesis abstract: Driven piles in granular soils gain shaft capacity after installation in a phenomenon known as “pile set-up”. Set-up effects in sand have not been incorporated into design procedures largely because the underlying mechanisms are not well understood. This thesis reports a micromechanical investigation of pile set-up effect in sand using a newly developed fracture-based DEM model for simulating time-dependent behaviour in sand. Creep and stress relaxation around the pile have been widely discussed as possible underlying mechanism for pile set-up effect. Following the idea that creep and stress relaxation in sands are frequently accompanied by grain breakage, a new model based on the discrete-element method (DEM) to simulate creep/stress relaxation in sands was proposed. The model aims for conceptual simplicity, computational efficiency and ease of calibration. To this end a new form of normalized Charles power law is incorporated into a DEM model for rough crushable sands based on the particle splitting technique. The creep/stress relaxation time is advanced using an off-DEM ageing strategy. The model is validated by simulating creep/stress relaxation in quartz sands in oedometric and triaxial conditions. Model predictions are shown to compare favourably with experimental creep results in terms of creep strain, creep strain rates and particle breakage/GSD evolution, and with experimental stress relaxation results in terms of relaxed stress, stress relaxation rate, and GSD evolution.The fracture-based DEM model was then implemented to a centrifuge DEM chamber to simulated pile creep and pile set-up. Simulated pile creep settlements agree with observations in terms of pile creep parameter m and pile creep rate. Simulated pile set-up falls into the range of field observations for jacked piles. The results obtained indicate that particle breakage may play a significant role in set-up and represent the first validated modelling attempt of this complex phenomenon. To gain familiarity with DEM modelling of penetration problems, a DEM based CPT and SPT simulation on a volcanic sand was also conducted, using a virtual calibration chamber (VCC). The simulated CPT results are shown to capture well experiments from the literature over a range of density and confining stress. A good correlation between the energy-based equivalent SPT tip resistance with the CPT tip resistance can be observed if shaft resistance effects are discounted. SPT driven scheme may be used for simulating pile driven in the future study once proper driven parameters are determined.

Committee:
     PRESIDENT: GÓMEZ HERNÁNDEZ, JAIME
     SECRETARI: SANCHEZ VILA, FRANCISCO JAVIER
     VOCAL: PROVOST, ALDEN
Thesis abstract: Aquifers are naturally heterogeneous systems across multiple scales, which poses a known difficulty for grid-based solvers of solute transport. When advection is the dominant transport mechanism, concentrations obtained from these solvers are prone to be influenced by oscillations and numerical diffusion, causing a negative impact upon the calculations related to chemical reactions. Particle methods are free of these issues thanks in part to advection being incorporated into the particle displacement. Therefore, simulations based on particles lead to an improved description of complex transport processes and related metrics, motivating their consideration for simulating reactive transport through aquifers. Nevertheless, limitations related to computational efficiency, or the availability of particle-based programs, still influence the ability of these methods to reach the end-users and real-world studies. The objective of this thesis is to contribute to the development of particle methods for reactive transport modeling in aquifers. The work provides novel methodologies, complemented by computer programs that can be integrated into the workflow of modelers. The first part of the thesis focuses on the progressive development of a solute transport code based on the Random Walk Particle Tracking (RWPT) method. Several components needed to be developed to achieve a functional program seamlessly integrated with groundwater flow models employed by hydrogeologists. The work began by implementing parallel capabilities into a well-known particle tracking code, which is the base for the main program. A complementary module provides the smoothed reconstruction of concentrations, compatible with non-uniform-weight particle sets and three-dimensional domains. These merge into a single major program implementing RWPT, which also required the formulation of a new method to displace solute particles exactly to the interface of a flow-model cell. The product of these developments is a new multispecies solute transport code, integrating several other functionalities necessary for reactive transport studies. The thesis continues with a chapter presenting a review of the Smoothed Particle Hydrodynamics (SPH) method, focusing on its ability to simulate anisotropic dispersion in heterogeneous porous media. The potential of SPH for this kind of problem is recognized in the literature. However, an unphysical effect seems to have hindered its adoption for practical studies: conservative simulations present negative concentrations in scenarios with anisotropic dispersion. To address the issue, three different SPH formulations were evaluated, discussing the origin of negative concentrations. This chapter presents the first application of the SPH method to an aquifer with an explicit representation of heterogeneity and dispersion anisotropy, without negative concentrations. The potential of the method for applications related to mixing-controlled reactive transport is discussed, and one of the formulations stands out as a robust solver in terms of the particles’ disorder, for a wide range of dispersion anisotropies. The thesis finalizes with a new nonlinear formulation of multicomponent reactive transport with species-specific dispersion properties. The study is motivated by a recurrent assumption in the literature considering dispersion coefficients to be the same for all chemical species. However, recent experiments have shown that specific diffusion coefficients limit transverse mixing, controlling the extent of reactions. A new expression for computing reaction rates while accounting for differences in transport coefficients is presented. This expression explains nonlinear mixing processes proportional to the differences in transport coefficients, which are also influenced by the chemical signature of the input solutions.

Committee:
     PRESIDENT: VILLAR GALICIA, MARÍA VICTORIA
     SECRETARI: LLORET MORANCHO, ANTONIO
     VOCAL: JOMMI, CRISTINA
Thesis abstract: Bentonite-based materials with low permeability, great water retention and self-sealing properties have been extensively used for engineered barriers in waste disposal facilities. Several typologies of bentonites exist. On the one hand, during installation, powder bentonites can release and disperse fine particles, while pouring bentonites in the form of pellet/powder mixtures can lead to particle segregation. On the other hand, sand/bentonite mixtures have a lower swelling potential compared to pure bentonites. Highly compacted bentonite blocks are more laborious to install and their use could hinder the release of gases formed in long-term operational facilities. These technological challenges could be addressed by using granular bentonite (GB), which has millimetre-sized granules and micrometre-sized grains, along with an extended particle size distribution (PaSD) (Fuller) that improves workability and pourability. Additionally, GB contains numerous macropores that allow gas release at low pressures. Consequently, GB is emerging as a reference material for engineering barriers. However, the geotechnical properties of GB remain poorly understood, particularly in terms of sample preparation, particle size and microstructural evolution and its correlations to hydro-mechanical (HM) and gas transport behaviour and self-sealing capacity. The Thesis provides robust, systematic, multi-scale experimental and theoretical frameworks for studying these aspects. The outcomes offer new particle-scale insights into the preparation technique of GB samples and how it affects the HM behaviour (e.g. compressibility on loading, volumetric expansion/collapse and swelling pressure on wetting under different stress and displacement boundary conditions) and its microstructure. A straightforward methodology combining Mercury Intrusion Porosimetry (MIP) and X-ray Micro-Computed Tomography (Micro-CT) has been proposed to improve the characterisation of compacted GB’s granular-type microstructure. Based on this methodology, compacted GB’s HM behaviour (e.g. swelling pressure, water permeability) can be further analysed from the pore-scale perspective, which displays a wide range of sizes. This microstructural information has also served as the basis for developing a multi-scale and multi-physics constitutive model of water retention behaviour. Moreover, the granular-type fabric with numerous and large interconnected macropores has been found to limit entrapped gas accumulation under partially saturated states while its gas transport properties also depend on how the initial microstructure evolves in response to gas pressurisation. The gas migration pathways at different HM states have been tracked by imaging techniques, which have subsequently used to define a model that incorporates this unique microstructure and its evolution to predict gas permeability. Furthermore, the granular-type microstructure with many high-density granules influences the sealing of technological gaps during loading and saturation. After gap-sealing, the HM behaviour of compacted GB is governed by the microstructure of the matrix set on compaction (the artificial gap insertion affected the compaction). The geometry of residual gaps after loading and saturation paths determines whether they could serve as preferential pathways for water and gas flow. In conclusion, this Thesis contributes meaningful information for evaluating the short- and long-term behaviour of GB as a geomaterial for engineered barriers.

Committee:
     PRESIDENT: CARRERA RAMIREZ, JESUS
     SECRETARI: SAALTINK, MAARTEN WILLEM
     VOCAL: DE SIMONE, SILVIA
Thesis abstract: Deep geological disposal is currently the preferred option for managing long-lived and heat-emitting radioactive waste. This method involves confining the waste for an extremely long period, potentially severa! hundreds of thousands of years, by placing it in a deep geological formation. Therefore, understanding the migration of gases produced by metal corrosion, microbial degradation, and radiolysis of water within a deep geological repository is crucial for assessing the repository's performance and long-term evolution. The primary objective of this study is to enhance the predictive capability of numerical models for understanding the processes and mechanisms of fracture initiation and growth in claystones with inherent heterogeneity and anisotropy, especially under rapid gas overpressure increases. To achieve this, geostatistics were applied into the finite element method software CODE_BRIGHT to generate a spatially correlated heterogeneous field for porosity. In CODE_BRIGHT, properties such as Young's modulus, intrinsic permeability, and thermal conductivity are functions of porosity, making these properties heterogeneous as well. Additionally, the solution of Eshelby's problem was implemented to introduce both heterogeneity and anisotropy in Young's modulus. lt is crucial to select the appropriate constitutive laws to effectively introduce anisotropy in intrinsic permeability. Simulations were conducted to validate the proposed framework, and sensitivity analyses were performed at both laboratory and in-situ experiment scales to assess the model's performance. The results indicate that the proposed model successfully captures the main observed features of heterogeneous anisotropic claystones during gas injection, including the formation of preferential gas pathways.