The two crucial shape factors (elongation ratio and flatness ratio) of brittle particles may influence the dynamic breakage of brittle particles upon impact. Hence, three-dimensional discrete element method simulations of brittle rock blocks with different shapes upon normal impact were performed. The simulated results indicate that the elongation ratio, that is, ratio of width to length and flatness

This study investigated theshear slip behavior and contact area evolution of rough rock discontinuities with impact shear load. First, the dynamic impact shear numerical simulation of rock samples with real rough rock discontinuities was carried out. Subsequently, the variety rule of slip displacement and velocity of rock discontinuity with impact velocity, confining stress and joint roughness coefficient

Fabric influences the macro scale mechanical properties and behavior of granular materials as a continuum and can be represented by an appropriately defined evolving fabric tensor entering the constitutive equations. In this study, the evolution of fabric tensors under cyclic loading is investigated and quantified by a series of cyclic loading DEM tests. Simulations of the DEM data are made by two

Soils are known to be inherently anisotropic, resulting in complex responses to loading. This paper aims to develop an elastoplastic solution for the undrained expansion of a cylindrical cavity in sands adopting a non-associated and anisotropic model, SANISAND. The rigorous derivation of the stress-strain state of the soil element is provided following a standardized solving procedure. The dilatancy

We develop an analytical solution to the problem of one-dimensional consolidation of unsaturated soil subjected to cyclic loads with arbitrary waveforms. The solution predicts the excess pore water and pore air pressures and the accompanying vertical compression in a poroelastic, unsaturated soil material. Cyclic loading occurs in a variety of engineering applications and often generates higher excess

When an explosive column initiates, it will radiate P-SV waves. The propagation of P-SV waves, which carry the majority of the explosion energy, is extremely complex in jointed rock masses. Therefore, studying the propagation of blasting stress waves in jointed rock masses is of great significance for optimizing the parameters of the blastholes and improving the economy and safety of geotechnical engineering

Ascertaining failure mechanism is a prerequisite of the derivation for earth pressure against retaining structures. Retaining structures constructed adjacent to existing structures and excavation with narrow backfill have become common in practical engineering. The backfill width has a significant effect on the failure mechanism, requiring further study. In this study, a series of discrete element

We develop automated methods for fault detection utilizing static stress and deformation fields at the onset of failure derived from numerical analysis. We calculate combinations and normalization of the distance from the Mohr circle to the Coulomb envelope, and of the second deviatoric strain invariant. A variation of the Cauchy distribution of these fields allows us to focus on the low values indicating

Hydraulic fracture, whether a natural phenomenon or an engineered process, consists of a highly pressurized flow evolving within a rock and, when necessary, fracturing such a medium. Particularly, in the context of oil and gas exploitation, a mixture of water and proppant is injected through a well to improve the oil extraction conditions by artificially increasing the local permeability. From a modeling

As yielding supports can deform without being damaged, the yielding principle has attracted significant attention for tunnelling in squeezing ground compared with the heavy support method. The deformation energy of surrounding rock can be managed using yielding supports that maintain the rock pressure within the bearing capacity of the supports. However, although the yielding principle has been often

The drying shrinkage of porous materials is significantly dependent on external relative humidity ( R H e $RH^{e}$ ). The perspective of temperature increase due to the climate change will accentuate the drying phenomenon in structures in lands and cities. The evolution of shrinkage can be determined by equivalent pore pressure consisting of capillary pressure P c $P_c$ , disjoining pressure and pressure

Non-uniformly distributed in-situ stress around the tunnel is a significant factor inducing various geohazards during tunnel excavation in the rock mass, and the anisotropy of the rock mass would further differentiate the in-situ stress state around the tunnel. To ensure the safety of tunnel construction and operation, it is necessary to deeply analyze the stress distribution law and mechanical mechanism

In this article, we investigate the creep mechanism of clay at the nanoscale. We conduct the molecular dynamics (MD) modeling of clay samples consisting of hexagonal particles under compression and shear. The MD simulations include oedometer creep, shear creep, direct shear tests, and stress relaxation. The numerical results show that the nanoscale creep mechanism of clay is related to particle rotation

The characteristics of seabed ground motion are the theoretical basis for the study of seawater-soil-structure interactions and seismic-induced geological hazards. There are numerous offshore marine structures located on sloping seabeds. Therefore, the sloping seabed's seismic response requires to be investigated. Engineers and scholars are more interested in the SV waves because they carry more energy

A viscoplastic constitutive model is developed to describe the viscoplastic behavior of unsaturated soils. The proposed model accounts for the stain-rate and suction effects on yield by adopting an unsaturated isotach concept. The nonstationary flow surface theory (NSFS) is applied for modeling the viscoplastic behavior, with the yield surface which can evolve with the viscoplastic strain, viscoplastic

With the increasing demand for transportation construction in coastal areas, tunnel safety research is becoming increasingly important. Previous studies take less account of the nonlinear wave and current action under the sloping seabed terrain. Furthermore, there are few researches on the additional deformation of shield tunnel lining caused by wave-current dynamic pressure. In this paper, according

The paper presents a comparative analysis of three systems of dynamic equations for fluid-saturated solids: the exact equations and two simplified versions known as the u-p approximations obtained by neglecting certain acceleration terms in the exact equations. The constitutive relations for the solid skeleton are written in the general anisotropic incrementally linear form without considering any

The de la Cruz and Spanos (dCS) theory of poroelasticity is a pore-scale volume averaged formulation and differs from the widely used Biot (BT) theory. A novel Finite Element Method (FEM) is developed for dCS theory to enable the study of nonreciprocal solid–fluid interactions, which are omitted from BT model. Solid deformations are quasi-static and pore fluid flow is transient; dynamic effects are

Adopting the novel proposed unified strain-hardening and strain-softening (UHS) model and finite difference method, an efficient semi-analytical solution is proposed to study the influence of the nonlinear behavior of rock on ground reaction. The proposed solution eliminates stress vibrations of the classical method that occurred in the strain-hardening zone, because it judges the elastic or plastic

The stratigraphic uncertainty and rotated anisotropy of soil properties exist widely in nature. Recent studies have shown that the slope stability was significantly influenced by these two uncertainties. However, there is no proper method for simulating these two uncertainties at the same time, and the influence of the two uncertainties has not been considered in previous unsaturated soil slope stability

This paper presents further improvements to the neohypoplasticity (NHP), a constitutive model for sand, which overcomes some shortcomings of widely used hypoplastic models. The novelties presented in this paper includes a new description of the additional dilatancy due to the structural variable z $\bm {z}$ and the introduction of a new state variable, denoted as h r $\bm {h}^r$ , to consider the small

This paper aims to investigate the seepage process of fractured rock mass at a mesoscopic level, using the discrete element method. To this end, an improved pipe flow algorithm is proposed within the framework of particle flow code, including the heterogeneity of initial micro-cracks and the deformation of solid skeleton. A series of numerical samples with a single non-penetrating fracture are then

In this paper a phase-field formulation based on an extended F-criterion (the normalized strain energy release rate criterion) is proposed to simulate tensile-compressive-shear rock fractures. By applying the F-criterion, the phase-field crack-driving energy decomposition is determined by a direction search which maximizes the local fracture dissipation. In compressive-shear states, the computation

Riverside landslides can induce surge waves during the process of entering water. The landslide-induced surge wave is often regarded as a significant secondary disaster, as its impact region is likely to be even more remarkable than the landslide itself. Due to the large deformation of the soil landslide and water body during the evolution of surge waves, commonly adopted multi-phase flow models and

On the strength of the capillary physical equivalent model and heat transfer law of series-parallel combined structural unit, the calculation model of effective thermal conductivity of coal-rock mass is obtained. The model considers the effect of roughness, porosity factor and other factors on effective thermal conductivity. CT digital core technology is applied to reconstruct the 3D model of coal-rock

A number of problems encountered in the field of computational geotechnics requires the modelling of numerous pile-type structures embedded in a three-dimensional soil continuum. Traditional modelling approaches to this problem result in computational costs that must be regarded as unbearable for most practical purposes. As an attractive alternative, we propose an enhanced embedded FE model with implicit

The determination of critical failure surface and stability evaluation of 3D slopes have been a hot and difficult problem in geotechnical engineering. The conventional method defines the critical failure surface using the safety factor (SF) whereas it is powerless for some special problems, such as two different failure surfaces with equal SFs. So far, many studies on the critical failure surface of

This study focuses on the mathematical interpretation and consolidation behavior of unsaturated composite ground with floating permeable columns (FPC). By combining the axisymmetric consolidation model with the equal strain assumption, the consolidation problem of unsaturated composite ground with FPC is transformed into a one-dimensional consolidation problem of an equivalent double-layer ground.

This paper presents a 3D spectral numerical scheme that can accurately model planarcracks of any shape residing on an interfacial plane between two elastic solids. The cracks propagate dynamically under the action of interfacial loads and interfacial constitutive laws. The scheme is a spectral form of the boundary integral equations (BIE) that relate the displacement discontinuity fields along the

Fluid injection-induced deformation around a cylindrical cavity is of particular interest in the area of subsurface energy extraction. In this study, a model is proposed to analyze the time-dependent expansion of a cavity caused by fluid injection in an elastoplastic dry porous medium. This problem is characterized by the existence of two moving boundaries, a permeation front and an elastoplastic interface

This paper presents a numerical study of the effects of the particle's shape and its interaction with surrounding fluid on the mechanism of sandpiles formation in air and water, respectively. This study is motivated by the fact that seabed sediments are predominantly deposited in water and consist of non-spherical particles. In our study, a non-linear contact model is employed in the Discrete Element

The elastic viscoplastic properties are non-negligible factors of clays that cause the deviation between the theoretical and the measured values, which were rarely incorporated in layered consolidation problems. Thus, this paper extended a generalized bi-layered one-dimensional (1D) consolidation model for soft ground under ramp load, simultaneously incorporating elastic viscoplastic deformation, non-Darcy

Dynamic wave reflections would interfere with the laboratory observation of the soil arching under cyclic loading when a traditional trapdoor model with rigid boundaries was used. This problem would be prominent when investigating the soil arching in pile-supported embankments where the stationary support (pile) would be small, making the rigid boundary close to the domain of interest affected by dynamic

Frost heave can lead to both the ground uplifting and frost heave pressure under different circumstances, and cause many engineering problems. To describe the characteristics of frost heave under various thermo-hydro-mechanical (THM) coupling conditions and calculate both the frost heave amount and the frost heave pressure, the coupled THM process, as well as the phase change of the pore water, should

Bituminized waste products (BWPs) were produced by conditioning in bitumen the co-precipitation sludge resulting from industrial reprocessing of spent nuclear fuel. Underground geological disposal is a solution for the long-term disposal of some intermediate level long-lived (ILW-LL) categorized BWPs in France. After one or several hundred thousand years, the water from the host rock will fully saturate

Strainburst often occurs in the loading process of tangential stress concentration from surrounding rocks after excavation and unloading of deep rock mass. The concentrated tangential stress is relatively larger on the tunnel walls, which decreases towards the interior of surrounding rocks with a certain gradient. To explore the fracture evolution characteristics of surrounding rocks under different

Landslide motion is often simulated with interface-like laws able to capture changes in frictional strength caused by the growth of the pore water pressure and the consequent reduction of the effective stress normal to the plane of sliding. Here it is argued that, although often neglected, the evolution of all the 3D stress components within the basal shear zone of landslides also contributes to changes

The paper presented a novel analytical solution to evaluate the seismic-induced stresses and displacements of tunnels covered by an isolation coating layer subjected to SH waves. The solution is derived based on the assumptions that the ground, isolation coating layer, and liner are linear elastic and in steady-state motion. The analytical solution is obtained using the Bessel-Fourier series. Comparisons

The development and calibration of soil models under the framework of plasticity is notoriously challenging given the prismatic features in soil's shear behaviors. Data-driven deep neural networks (DNNs) offer an alternative approach to this formidable task. However, classical DNN models struggle to accurately capture soil mechanical responses using limited training data. To address this issue, a unified

The smoothed particle finite element method (SPFEM) is an effective framework for large deformation analysis. The original SPFEM possesses the rank deficiency issue due to the direct nodal integration technique, which can be overcome by incorporating the strain gradient stabilization method. However, an extra volumetric locking due to the strain gradient stabilization term has been found. In this study

This note presents an exact analytical solution of Fredlund–Hasan consolidation for unsaturated soils under an arbitrary loading using the mode superposition method. Air pressure and water pressure are expressed in a series of products of Eigen functions with respect to depth and normal coordinates with respect to time, respectively. A pressure function substitutes for the related homogeneous problem

This paper provides the solution of a homogenization model that simultaneously considers the plastic and elastic strain fields in a single analytical formulation. In addition, the authors aim to decouple plastic flows triggered in the inclusions, in the matrix at the interfaces with the inclusions, and in the matrix at a large distance from the inclusions. The authors propose an admissible displacement

Excavation damaged zone (EDZ) widely exists in the surrounding rock of underground roadway due to blasting excavation, which can further change the surrounding rock property and deteriorate the stability of the roadway. In the presented research, a damaged roadway model was developed to investigate the dynamic stress concentration factor (DSCF) distribution around the damaged roadway under a transient

Clay rocks are multiphase porous media having a complex structure and behaviour characterised by heterogeneity, damage and viscosity, existing on a wide range of scales. The mesoscopic scale of mineral inclusions embedded in a clay matrix has an important role in the mechanisms of deformation under mechanical loading by cracking and creeping. This study introduces a micromechanical approach to model

This study proposes a new model in explicit form to predict the diameter of the jet grouting column of three popular jet grouting systems (i.e., single, double, and triple). The proposed model can quantify the uncertainty associated with the prediction. Bayesian model selection was used to determine the optimal models and, the bootstrap sampling method was adopted to avoid bias in the collected database

Reliability analysis of earth slopes considering soil spatial variability has garnered significant attention from researchers. However, previous studies have predominantly focused on long slopes with infinite or ample width, such as dams and subgrades, but rare research was dedicated to slopes with width restricted by boundary constraints. In this regard, this paper proposes an efficient reliability

Hydrothermal ore-forming systems usually involve coupled processes among pore-fluid flow, heat transfer, mass transport and chemical reactions in fluid-saturated porous media. The finite element method (FEM) has provided a powerful tool to solve hydrothermal ore-forming problems associated with pore-fluid convective flow. Depending on different interests of research, a hydrothermal ore-forming system

Many geo-engineering applications, for example, enhanced geothermal systems, rely on hydraulic fracturing to enhance the permeability of natural formations and allow for sufficient fluid circulation. Over the past few decades, the phase-field method has grown in popularity as a valid approach to modeling hydraulic fracturing because of the ease of handling complex fracture propagation geometries. However

We present a hypoplastic model to capture the mechanical responses of hydrate-bearing sands by incorporating hydrate saturation and grain breakage. In our model, a new degradation scalar is introduced to account for the effects of hydrate bonding evolution on strength. We also adopt the variable critical state line to assess the effects of hydrate saturation and relative breakage ratio at high confining

The susceptibility of a granular soil to suffusion is strongly dependent on its grain size distribution (GSD) and the mechanical and hydraulic conditions it is subjected to. This study investigates the onset of suffusion considering the effect of confining pressure and stress anisotropy using a fully resolved computational fluid dynamics and discrete element method (CFD–DEM). Three benchmarks, including

Continuous drainage boundary is widely accepted to overcome the shortcoming of the traditional assumption of fully permeable or impermeable drainage boundary in consolidation theories. This study presents an analytical solution for one-dimensional small-strain nonlinear consolidation of saturated multi-layered soil with constant consolidation coefficients under continuous drainage boundary condition

This paper presents a novel method for evaluating the resistance factor used for the estimation of lateral pile capacity in cohesive soil. The developed method uses limit equilibrium and mobilized strength principles, which are implemented on the half-symmetric problem using a modification of the traditional slice method. The soil medium is discretized into a polar numerical grid, allowing sliplines

A novel mixed enriched finite element model is developed for coupled non-linear thermo-hydro-mechanical simulation of fractured porous media with three-phase flow and thermal coupling. Simulation of induced acoustic emission (AE) and microseismic emission (ME) due to tensile fracturing and shear slip instability of pre-existing fracture interfaces is carried out and the numerical results of the emitted

The fiber-reinforced polymer (FRP) has attracted much attention in civil engineering due to its durability and cost-effectiveness. The soil–FRP structure interface plays an essential role when the FRP is adopted in geotechnical engineering, but its fundamental interfacial behavior remains unclear. In the present study, the atomistic models of silica representing sand, water film representing the lubricated

Fluid flow in deformable fractures is important to many applications including hydraulic stimulation. Fracture flow simulations typically rely on the Poiseuille flow model which presumes laminar quasi-steady-state flow conditions with negligible inertia. The high flow rates involved in industrial applications bring these assumptions into question. The GG22 flow model is a new method to capture inertial

Recently, a fluid volume enrichment strategy based on the asymptotic solutions near the crack tip was proposed for fluid-driven fracture propagation problems. Despite its successes in various benchmark and field-scale problems of hydraulic fracturing simulations, the aforementioned enrichment strategy has the following limitations. First, the tightly coupled solid-fluid nonlinear system cannot be consistently

Cemented sands exhibit superior mechanical properties compared to clean sands. Based on this evidence, ground improvement methods are increasingly employed to induce cementing reactions that can bind the solid particles of sands and other soils for the ultimate enhancement of their properties and behavior. Despite increasing ground improvement applications, constitutive models capable of capturing

With the shift of the offshore wind energy sector to deeper waters, demand for the development of more complex foundation solutions, particularly suction bucket – supported tripod/tetrapod and jacket foundations, has increased. This paper is divided into two main sections. The first part comprises a comprehensive review of the performance of circular surface and shallow foundations under combined loading

Due to the installation of energy piles, the surrounding soil will be inevitably disturbed, leading to a smaller void ratio and larger thermal conductivity. This study proposes a new closed-form solution to calculate the heat exchange of energy pile foundations considering smear effects on the different soil thermal properties in the smear zone and undisturbed zone. The analytical model adopts the

A governing equation for large-strain consolidation of PVD-improved soil is developed based on the equivalent elliptical cylindrical model, which accounts for depth-dependent initial void ratio and initial effective stress induced by soil self-weight, well resistance with variable discharge capacity, time-dependent load, and nonlinear variations of compressibility and permeability. Then, a numerical