Zhen-Yu Yin

• The Hong Kong Polytechnic University

A novel framework for nonlinear thermal elastic-viscoplastic (TEVP) constitutive relationships was proposed in this study, incorporating three distinct thermoplasticity mechanisms. These four TEVP formulations, combined with an existing TEVP constitutive equation presented in the companion paper, were integrated into a coupled consolidation and hea...

Physics-informed neural network (PINN) prevails as a differentiable computational network to unify forward and inverse analysis of partial differential equations (PDEs). However, PINN suffers limited ability in complex transient physics with nonsmooth heterogeneity, and the training cost can be unaffordable. To this end, we propose a novel framewor...

The characteristics of the consolidation facilitated by prefabricated horizontal drains (PHDs) combined with vacuum loading, and the evolution of the soil column surrounding the PHDs, which significantly affects the acceleration efficiency, remain insufficiently understood. This study conducts experimental investigations into PHD-assisted consolida...

Contact problems are of paramount importance in engineering but present significant challenges for numerical solutions due to their highly nonlinear nature. Recognizing that contact problems can be formulated as optimization problems with inequality constraints has paved the way for advanced techniques such as the Interior Point (IP) method. This s...

This study first invents a novel oedometer apparatus for clay slurry, featuring a lightweight acrylic loading cap, a noncontact laser displacement sensor, and a 1:1 dead-weight loading system to improve traditional consolidation devices. The novel apparatus is then used to examine two clays: Hong Kong Marine Deposit and Kaolin clay. The loading wit...

Micro-nano-bubbles (MNBs) offers a sustainable solution for remediating organics-contaminated groundwater. The transportation of MNBs in idealized porous media systems has been investigated through a series of experiments to deepen the understanding of MNBs migration. Based on an evaluation of the stability of MNBs, it was determined that dissolved...

Epidote is a common and abundant metamorphic mineral in geothermal systems driven by hydrothermal–rock interaction. Precipitation of epidote on natural fracture/fault surfaces potentially alters frictional resistance and stability in geothermal reservoirs and thus the potential to spawn earthquakes. Elevated pressures due to fluid-injection during...

Three-dimensional (3D) particle reconstruction from X-ray micro-computed tomography (μCT) images is essential for digital twins and understanding the micromechanical behaviors of granular media. Despite Large Vision models (LVMs) having shown remarkable effectiveness across various domains, their application to accurate 3D particle reconstruction r...

This paper presents a plastic-hardening, nonassociated macroelement model for predicting the load–displacement responses and padeye trajectories during the monotonic pullout process of suction anchors under horizontal–vertical–torsional loading (H–V–T) in clay. The closed-form formula of the three-dimensional H–V–T failure surface is established th...

Seabed trenching is a common geological and geotechnical hazard encountered in offshore engineering, potentially compromising the pull-out capacity of suction anchors and posing risks to mooring systems over time. Currently, to ensure conservative design and facilitate modelling convenience, many relevant studies simplify the trench configurations...

Artificial ground freezing (AGF) is a widely used technique for soil stabilization and waterproofing. Numerous studies have been devoted to solving the heat transfer problems in AGF while encountering limitations in handling complex geometries and boundary conditions and being computationally intensive. Recently, using machine learning methods to p...

Machine learning’s integration into reliability analysis holds substantial potential to ensure infrastructure safety. Despite the merits of flexible tree structure and formulable expression, random forest (RF) and evolutionary polynomial regression (EPR) cannot contribute to reliability-based design due to absent uncertainty quantification (UQ), th...

This paper develops a new time-dependent hypoplastic model for normally consolidated and overconsolidated clays. A novel viscous strain rate formulation is derived from the isotach concept and incorporated into the total strain rate of the hypoplastic framework, allowing for viscous deformation at the onset of loading. The hypoplastic flow rule is...

This paper presents a novel application of a Glass Fibre-Reinforced Polymer (GFRP) tube filled with sand as an anti-corrosive pile wall system in harsh environments. The physical model set-up is first established to conduct a series of tests for assessing the performance of the wall. Optical Frequency Domain Reflectometry technology is employed to...

Elastoplastic theory is ubiquitous in engineering for modelling the mechanical behaviours of various materials such as metals and granular matter. Elastoplasticity allows computation of plastic strains and updated stresses with hardening parameters using explicit and/or implicit integration algorithms, requiring strong mathematical and domain knowl...

The microstructure of microbially induced carbonate precipitation (MICP) stabilized soils is typically used to explain the macro‐scale properties of the soils. However, the microstructure is usually inferred from scanning electron microscopy results after breakage, as directly observing the processes inside the pores is challenging. Microfluidics t...

This study presents a fully resolved numerical method coupling framework for capturing the interaction between debris flows and flexible barriers. The proposed coupling method combines a simplified flexible wire representation, smoothed particle hydrodynamics (SPH), and discrete element method (DEM). Specifically, the flexible wire representation i...

Microbially induced carbonate precipitation (MICP) has been extensively studied through experiments as a potential solution for ground improvement. However, the investigation and optimization of the MICP grouting process remain incomplete due to various experimental limitations, such as budget constraints, equipment availability, time limit, and su...

In an effort to enhance engineering infrastructure and reduce environmental waste, the use of COVID-19 face-mask chips (FMC) in sand reinforcement is experimentally explored through drained hollow cylinder torsional shear tests, including monotonic stress paths with different fixed orientation of the principal stress axes and cyclic tests with traf...

Physics-informed neural networks (PINNs) are well-regarded for their capabilities in inverse analysis. However, efficient convergence is hard to achieve due to the necessity of simultaneously handling physics constraints, data constraints, blackbox weights, and blackbox biases. Consequently, PINNs are highly challenged in the inverse analysis of un...

The interfacial tribology between clay and sand could significantly affect the mechanical stability of soil structures, while it remains unclear in the microscale. In this study, molecular dynamics (MD) simulation method has been employed to investigate the nanoscale friction behavior between quartz and montmorillonite at dry state, where quartz an...

Granular flow is ubiquitous in various engineering scenarios, such as landslides, avalanches, and industrial processes. Reliable modeling of granular flow is crucial for mitigating potential hazards and optimizing process efficiency. However, the complex behavior of granular media, which transitions between solid‐like and fluid‐like states, poses a...

Accurately imposing boundary conditions and contact constraints in the Material Point Method (MPM) and its coupling with the Finite Element Method (FEM-MPM) is challenging, especially when dealing with complex geometrical shapes and misalignment between material boundaries and the computational grid. To address these issues, an improved explicit pe...

Accurate estimation of soil properties is crucial for reliability-based design in engineering practices. Conventional empirical equations and prevalent data-driven models rarely consider uncertainty quantification in both measurement and modelling processes. This study tailors three uncertainty quantification methods including Bayesian learning, Ma...

This paper develops a novel Hybrid Particle Element Method (HPEM) to model large deformation problems in solid mechanics, combining the strengths of both mesh-based and particle approaches. In the proposed method, the computational domain is discretized into two independent components: a set of finite elements and a set of particles. The finite ele...

Fiber-reinforced polymer (FRP) is widely used in various engineering fields due to its several outstanding properties. In geotechnical engineering, the interactions between FRP and soil play an essential role. In this paper, molecular dynamics (MD) simulation method has been performed to study the interfacial mechanical behavior of epoxy-quartz int...

Reconstructing three-dimensional (3D) granular microstructures through X-ray micro-computed tomography (μCT) imaging is significant for elucidating micromechanical behaviors of granular media and optimizing geotechnical designs. However, due to the irregular morphology and dense packing of granular media, traditional image-processing techniques oft...

The friction behavior of widespread clay minerals is a major concern in many geo-engineering problems, such as the stability of soft soil foundations and the induction of seismic fault zones. The present work aimed to study the friction behaviors of kaolinite at the particle level using the molecular dynamics method. The effects of normal force (Fn...

The use of horizontal drains assisted by vacuum loading is an effective method for speeding up the consolidation of dredged soil slurry. However, few studies developed models for the large strain consolidation of clayey slurry with prefabricated horizontal drains (PHDs) under self-weight and vacuum loading considering the effects of nonlinear compr...

The complex morphologies of particles are a crucial factor influencing suffusion in gap-graded granular soils. However, the micro-mechanism of soil suffusion composed of irregular concave particles remains unclear. To this end, a systematic numerical simulation that considers particle concavity and aspect ratio is performed with the resolved discre...

The formation of discontinuities within soil masses due to arching phenomena is a critical issue in geotechnical engineering, profoundly influencing the stability and integrity of underground structures. This study investigated the microscopic mechanisms and associated stress redistribution in the soil mass above an actively moving trapdoor. Utiliz...

Soil surface erosion can shape the morphography of rivers and estuaries in the natural environment and induce high potential risks to structures in engineering. Numerical simulations based on continuum mechanics theory can provide reliable assessments of the evolution of surface erosion from the perspective of a large-scale view. However, current s...

Calcareous sand has been used in reclamation for constructing artificial islands. It suffers different stress paths with varying constant incremental stress ratios (Δq/Δp'), exhibiting diverse mechanical characteristics with grain crushing. However, previous experimental studies mainly focused on conventional triaxial stress path (Δq/Δp' = 3). This...

The freeze-thaw cycles of frozen soil could significantly affect its thermo-hydro-mechanical-chemical (THMC) properties, causing the frost heaving and thawing settlement. The microscale essence is the water-ice phase transition, but the microscale details are still poorly understood, especially at ultra-low temperatures. Nuclear magnetic resonance...

CGJ

The micromechanical mechanism of upward pipe-soil interaction in unsaturated soil remains unresolved. This study investigates the upward pipe-soil interactions in dry and unsaturated granular soil through a sequence of coupled discrete element method and finite element method (DEM-FEM) simulations. The capillary suction effect was simulated using t...

The application of fiber-reinforced polymer (FRP) composites as piling materials in harsh environments has gained popularity due to their high corrosion resistance. FRP composites can be fabricated using different types of epoxy resin matrices and fibers. This study aims to investigate the interface behavior between sand and FRP materials with vary...

Fiber-reinforced polymer (FRP)-confined concrete tubular columns have been extensively studied, where the design of the column is usually based on stiffness and strength. The ability to sustain large deformations without losing structural integrity is also critical in geotechnical engineering. This paper proposes a novel high-ductility tubular colu...

The major principal stress direction angle (ασ) experienced by granular soils varies widely in engineering, causing different strengths. However, how particle morphology affects the strength anisotropy behavior under different ασ remains unclear. To address this gap, this study performed drained hollow cylinder torsional shear tests under different...

Classical numerical methods such as finite element method (FEM) face limitations due to their low efficiency when addressing large-scale problems. As a novel paradigm, the physics-informed neural network (PINN) has demonstrated significant potential to solve partial differential equations. However, conventional PINNs utilize meshless control at dis...

Contemporary geoengineering challenges grapple with the plateauing of both existing algorithms and their depth of insights, a phenomenon exacerbated by the scarcity of high‐fidelity data. Although existing solutions such as Monte‐Carlo method can generate abundant data, they are not sufficiently robust for ensuring the high fidelity of data. This s...

Fluid overpressure from the water released by subducted sediments and oceanic crust is an important mechanism for generating earthquakes via brittle failure and frictional instability. If unstable, such fault materials may also host diverse fault reactivation mechanisms from slow slip events to moderate-sized earthquakes in cold subduction zones. W...

This study proposes a refined approach for simulating the mechanical behavior of soils under high stress by integrating the finite difference method–discrete element method (FDM–DEM) with in situ experiment. This novel framework incorporates advanced technologies such as flexible membrane and X-ray computed tomography (CT) to enhance the predictive...

A novel ground improvement method that combines grid prefabricated horizontal drains (PHDs) with prefabricated vertical drain (PVD) assisted by vacuum preloading is proposed for the beneficial reuse of dredged clayey slurry for reclamation purpose. To assess the feasibility of this innovative method, physical model tests are designed and conducted...

The simulation of the soil–structure interface (SSI) under cyclic loading is critically important in geotechnical engineering. Numerous studies have been conducted to explore the cyclic behaviors exhibited at the SSI. However, existing model evaluations primarily rely on direct comparisons between experiments and simulations, with limited analysis...

This study investigates, for the first time ever, the suffusion on gap‐graded granular soils under torsional shear conditions from a microscopic perspective. A numerical model of the hollow cylinder torsional shear test (HCTST) using the discrete element method (DEM) is first developed, where an algorithm for simulating the real inner and outer rub...

A new simplified practical method for one‐dimensional nonlinear large‐strain consolidation of saturated homogenous soils is proposed. The derivation processes of the proposed method are introduced first, with a modification of Terzaghi's theory from a novel perspective to solve large‐strain consolidation problems. Verification checks of the propose...

Accurate three‐dimensional (3D) reconstruction of granular grains from x‐ray micro‐computed tomography (µCT) images is a long‐standing challenge, particularly for dense soil samples. This study develops a machine learning (ML) enhanced approach to automatically reconstruct granular grains from µCT images. The novel academic contributions of this pa...

The identification of geomaterial properties is costly but pivotal for engineering design. A wide range of approaches perform well with sufficiently measured data but their performance is problematic for sparse data. To address this issue, this study proposes an active learning based multi-fidelity residual Gaussian process (AL-MR-GP) modelling fra...

Land reclamations often demand large quantities of fill materials. However, many countries commonly engaged in land reclamation are facing an escalating scarcity of natural fill sources. To address this issue, this study proposes a sustainable land reclamation approach that involves dredged marine sediments as fill materials. The dredged marine sed...

The burgeoning demand for land resources in cities has spurred the development of intricate underground infrastructure networks. Therefore, evaluating the performance and stability of entire existing underground complexes in the event of construction-related disturbances becomes increasingly crucial for ensuring overall urban resilience. This paper...

Epidote is a common hydrous mineral present in subduction zones subject to greenschist metamorphic conditions – and potentially an important control on the fault stability-instability transition observed under greenschist facies. We explore controls on this transition through shear experiments on simulated epidote gouge at temperatures of 100–500 °...

The current mechanisms and factors influencing soil aging remain inconclusive and incomplete. Discrete element method (DEM) is adopted to investigate the responses of irregularly shaped granular assemblies subjected to creep and post-creep triaxial shear. The simulated creep and aging behaviours are generally in line with those observed in existing...

Handling contact problems in the Material Point Method (MPM) has long been a challenge. Traditional grid-based contact approaches often face issues with mesh dependency, while material point-based methods can be computationally intensive. To address these challenges, this study develops a novel mortar segment-to-segment frictional contact approach...

Physics-informed neural networks (PINNs) have recently prevailed as differentiable solvers that unify forward and inverse analysis in the same formulation. However, PINNs have quite limited caliber when dealing with concentration features and discontinuous multi-material heterogeneity, hindering its application when labeled data is missing. We prop...

With the increasing utilization of suction anchors in mooring systems, field surveys have observed seabed trenches near suction anchors caused by anchor chain motion and soil erosion. The presence of these trenches significantly reduces the pull-out capacity of suction anchors, emphasizing the need for attention. This study investigates the impact...

Numerous studies have investigated the coupled multi-field processes in frozen soils, focusing on the variation in frozen soils and addressing the influences of climate change, hydrological processes, and ecosystems in cold regions. The investigation of coupled multi-physics field processes in frozen soils has emerged as a prominent research area,...

This study introduces a novel, interdisciplinary method that merges fundamental geomechanics with computer vision to develop an advanced hybrid feature-aided Digital Volume Correlation (DVC) technique. This technique is specifically engineered to measure and compute the full-field strain distribution in fine-grained soil mixtures. A clay-sand mixtu...

The effect of breakable particle corners is often overlooked in research on pile–soil interaction, which hinders the understanding of the uplift pile behaviors in calcareous sand. This research examines the breakable corner effects on uplift pile–soil interaction in calcareous sand from macro to micro, through model tests and coupled discrete eleme...

Cavity expansion is a canonical problem in geotechnics, which can be described by partial differential equations (PDEs) and ordinary differential equations (ODEs). This study explores the potential of using a new solver, a physics-informed neural network (PINN), to calculate the stress field in an expanded cavity in the elastic and elasto-plastic r...

Most existing two-phase, two-layer Material Point Method (MPM) programs operate in explicit form, which lacks computational efficiency. This study proposes a high-performance semi-implicit two-phase two-layer MPM framework for modeling granular mass-water dynamic interaction problems based on mixture theory. This innovative approach employs two lay...

Frozen wall thickness (E) is an important index that reflects the freezing performance of artificial ground freezing (AGF). In previous design and numerical studies, the inherent spatial variability of soil properties is often neglected. Moreover, groundwater seepage can remarkably affect the freezing performance in the AGF system, while the specif...