Yue Ma

Bio: Yue Ma is an academic researcher from University of Leeds. The author has contributed to research in topics: Biot number & Osmosis. The author has an hindex of 1, co-authored 3 publications receiving 2 citations.

The influence of coupled physical swelling and chemical reactions on deformable geomaterials

Abstract: Coupled thermo‐hydro‐mechanical‐chemical modelling has attracted attention in past decades due to many contemporary geotechnical engineering applications (e.g., waste disposal, carbon capture and storage). However, molecular‐scale interactions within geomaterials (e.g., swelling and dissolution/precipitation) have a significant influence on the mechanical behaviour, yet are rarely incorporated into existing Thermal‐Hydro‐Mechanical‐Chemical (THMC) frameworks. This paper presents a new coupled hydro‐mechanical‐chemical constitutive model to bridge molecular‐scale interactions with macro‐physical deformation by combining the swelling and dissolution/precipitation through an extension of the new mixture‐coupling theory. Entropy analysis of the geomaterial system provides dissipation energy, and Helmholtz free energy gives the relationship between solids and fluids. Numerical simulation is used to compare with the selected recognized models, which demonstrates that the swelling and dissolution/precipitation processes may have a significant influence on the mechanical deformation of the geomaterials.

General analytical solutions for one‐dimensional nonlinear consolidation of saturated clay under non‐isothermal distribution condition

Abstract: The fluctuation of temperature leads to the changes of physical‐mechanical properties of clayey soils. In some practical projects such as landfills, the compacted clay liner is usually subjected to a non‐isothermal distribution state. For one‐dimensional nonlinear consolidation process of saturated clay under non‐isothermal distribution condition, the general analytical solutions considering time‐dependent loading are derived for the first time, where the methods of algebraic transformation and separation variable are used. Moreover, two forms of boundary conditions are included according to engineering practice. Referring to the proposed general analytical solutions, the expressions for the analytical solutions under instantaneous loading pattern and single‐stage linear loading pattern are developed. Besides, the correctness of the presented analytical solutions is validated by comparing with the existing analytical solutions and finite difference solutions. Based on the proposed analytical solutions, the influence of temperature gradient, final loading and loading time on the consolidation behaviors is analyzed. It is found that the increase in temperature gradient accelerates the consolidation rate, and the average volume compressibility coefficient decreases by 65.4% when final loading increases from 50 to 500 kPa. In conclusion, the analytical solutions proposed in this study are more comprehensive and can be applied in different engineering cases.

Coupled Thermo-Hydro-Mechanical-Chemical processes with reactive dissolution by non-equilibrium thermodynamics

Abstract: The Clausius-Duhem Inequality has been widely adopted to model the coupled Thermo-Hydro-Mechanical-Chemical processes. However, this paper points out that when modelling a reacting system, the Clausius-Duhem Inequality may hide the reaction mechanism and reaction type if the reaction changes the solid, and it may generate imprecise constitutive result if the reaction occurs within the fluid without changing the solid. To overcome these challenges, this paper proposed a novel non-equilibrium thermodynamics approach to model the multiphysics coupling processes with reactive dissolution. The new approach focuses on the Helmholtz free energy change in a dissolution process by quantifying the entropy production with the knowledge from non-equilibrium thermodynamics. A new concept, solid affinity, is introduced to give a better description of Helmholtz free energy change due to reactive dissolution. The coupled Thermo-Hydro-Mechanical-Chemical equations with reactive dissolution are derived by this approach. A numerical simulation is presented to show the role of quartz dissolution.

New Unsaturated Dynamic Porosity Hydromechanical Coupled Model and Experimental Validation

Abstract: Constitutive coupled modeling has developed rapidly in recent decades, with numerous new models published. However, few models consider dynamic porosity, and experimental validation of such a model remains a challenge due to multiple variables. In this study, a new constitutive model for unsaturated soil with dynamic porosity was developed based on mixture theory and nonequilibrium thermodynamics, then the model was validated using test data from two experimental studies that yielded good results (relative average error AVRE = 0.8631–1.3046, R2 = 0.9028–0.9981). The sensitivity of the model to the four primary parameters was analyzed to investigate the influence of model properties on the hydraulic and mechanical behavior. Results show that the calculation of volumetric strain is most sensitive to Young’s modulus (E), while the calculation of specific water volume is most sensitive to permeability (k). In addition, the sensitivity of the parameters changes with their value. Modeled results show that the porosity change significantly affects both hydraulic and mechanical behavior, even when soil undergoes relatively low deformation. Relative calculation error decreases notably after porosity change is considered (44.9% and 35.2% improvement in two different calculations). This study also finds that dynamic porosity affects the deformation energy of solids.