In this paper, a detailed numerical study is conducted to evaluate the lateral earth pressure acting on geosynthetic-reinforced retaining walls with an anisotropic granular backfill subjected to strip footing loadings. To this end, the well-established lower bound theory of limit analysis coupled with the robust second order cone programming (SOCP) and the finite element discretization method is exploited

Many studies have indicated that the triggering conditions for gravelly soil liquefaction are different from those for sandy soils. However, the existing prediction methods and models do not consider the differences. Moreover, most approaches of constructing Bayesian network (BN) models for predicting seismic liquefaction based on domain knowledge or data-driven are either too subjective or too objective

This paper describes a finite element study of the uplift behaviour of a plane strain pipe segment embedded in modified Cam clay soil. The primary aim of this study is to explore the role of rate effects on pipe uplift capacity and the transition between drained and undrained behaviour using coupled-consolidation analyses. The velocities considered in the modelling cover six orders of magnitude allowing

The contaminant transport of perfluorooctane sulfonate (PFOS) through the base of a municipal solid waste landfill lined by a single composite liner comprised of a geomembrane over a geosynthetic clay liner (GCL) and a 3.75 m-thick attenuation layer underlain by an aquifer is examined. Both pure diffusive transport and advective transport through holed wrinkles are modelled. The peak concentrations

In this paper, a new Lagrangian differencing dynamics (LDD) method is presented for the simulation of granular flows. LDD is a truly meshless method, which employs second-order consistent spatial operators derived from the Taylor expansion and point renormalization. A decoupled pressure-velocity formulation is employed to derive the pressure Poisson equation, which ensures smooth pressure results in

Kriging metamodel is an effective method for slope reliability analysis because of its flexibility and accuracy in data interpolation. However, the accuracy of traditional Kriging metamodel needs to be improved when facing complex limit state functions in slope stability problems. In addition, traditional Kriging metamodel cannot provide the key component—slope failure consequence—for risk assessment

An optimum design of mine pillars necessitates a reliable estimation of the rock mass strength. It is known that the Hoek-Brown failure criterion, with its strength parameters obtained using the Geological Strength Index, tends to underestimate the confined strength of interlocked jointed hard rock masses. Therefore, geomechanical designs based on this approach could lead to oversized pillars due to

The oedometric compaction of materials with collapsible structure is investigated from a numerical point of view. Such materials form planar zones of localized volumetric deformation that may or may not be accompanied by grain crushing. The purpose of the present work is to investigate the evolution of the permeability and its anisotropy as the result of the formation of compaction bands. The finite

The aim of this paper is to investigate the effect of an adsorbed water layer on the mechanical behavior of fine-grained wet granular materials in the pendular regime with isolated capillary liquid bridges. The adsorbed water forms a thin liquid film tightly bound to a particle’s surface equilibrated by a so-called “disjoining pressure”. In a stress transmission analysis, this disjoining pressure concept

The estimation of the wave-induced instantaneous liquefaction is particularly important for the design of foundations of offshore structures. Regarding the occurrence of liquefaction in a non-cohesive seabed, most existing studies using constant permeability were found to cause fallacious tensile stresses in the liquefied zone and further pollute the overall pore pressure distribution. A dynamic permeability

An algorithm is developed to estimate maximum and minimum horizontal stress using experimental data from sleeve fracturing experiments. The algorithm is developed by analyzing the crack initiation, propagation and interaction behavior between primary and secondary cracks based on the Finite Element Method with Cohesive Zone elements. Five key quantities can be obtained from data curves and comprise

As a temporary anchorage technique, recoverable anchors have been widely adopted in excavation supporting and underground mining for their unique economic and social merits. The current study attempts to investigate the load-transfer behavior of recoverable anchors in layer soils. The interaction between soil and grout was characterized by a new developed disturbed state concept (DSC) model, in which

This paper proposes a new 2D continuous-discontinuous heat conduction model to simulate heat transfer and thermal cracking in fractured quasi-brittle materials by combining with mechanical calculations of the Finite-Discrete Element Method. By updating the sharing relationship of the nodes at the cracks, the model can accurately predict the temperature evolution, crack propagation and considers the

Gassy soils are widely distributed in river deltas, coastal and marine sediments. The discrete bubbles, commonly formed in gassy soil, are sensitive to temperature and pressure variations and contribute to the changes in soil properties, e.g. compressibility and permeability. This paper develops a precise model, considering the effects of gas bubble thermal expansion, saturation degree (S) and distance

Fabric anisotropy underpins the mechanical response of granular soils pertaining to a wide range of practical geotechnical applications. This paper presents a multiscale computational study on a strip footing resting on an anisotropic soil foundation. The focus of this study is placed on examining the cross-scale links of key grain-scale mechanisms in the soil that underscore interesting macroscopic

Fiber reinforcement techniques can effectively optimize the engineering properties of ground soils. This study aims to investigate the influence of fiber stiffness on the shear behavior of fiber-reinforced granular soil. First, the particle shapes are automatically extracted based on the improved Viola–Jones algorithm. Subsequently, the fiber stiffness is calibrated considering the results of laboratory

Subsurface geological profiles often contain multiple soil layers, and spatial variability of soil properties within such a profile plays a crucial role in geo-structure analysis. Such spatial variability may be characterized through in-situ tests, e.g., cone penetration tests (CPT). However, the number of CPT soundings in a specific site is often small due to time, budget, and/or technical constraints

The purpose of this study is to present a plastic-damage model that can well capture the mechanical behaviors of rock-like materials. To this end, a three-invariant yield function combined with a cap function is employed to concurrently consider the physical mechanisms due to the presence of microcracks and pores as well as their combinations. The major contribution falls into the establishment of

Rock joints show a significant effect on the mechanical properties of rock masses. The existing constitutive approaches of rock joints focus on the complex shearing behavior while their accuracy still needs to be improved. In this paper, a reduced-order constitutive model of rock joints is proposed, which can accurately describe the shearing behavior in the whole displacement domain and can reduce

The preloading consolidation method has been widely applied to ground treatment. In this case, the top surface of unsaturated soil stratum is fully covered with a geosynthetics blanket to aid water and air flowing from the soil, which may cause uneconomic and wasteful design. This paper presents semi-analytical solutions of two-dimensional (2D) plane strain consolidation for unsaturated soils with

This study provides an analytical solution for forecasting one-dimensional molecular diffusion of organic pollutants in triple-layer composite liner system considering the coupling effect of thermal diffusion. The solution is appropriate for two typical bottom boundaries, i.e., Dirichlet and Neumann boundaries. The solution is verified against experimental data and a numerical method. Using the present

This paper extends the use of the skew boundary condition in two- and three-dimensional (3D) finite element analysis for both structural and geotechnical applications when the need of the freedom directions at the interface nodes is different from the global Cartesian directions. For instance, jack-up structures have three conical-shaped footings, whose freedom directions at the interface nodes are

Rolling dynamic compaction (RDC) is a ground improvement technique, which involves towing a non-circular module behind a tractor to achieve soil compaction. When compared against conventional static and vibratory compaction techniques, RDC is capable of compacting thicker layers of soil and at a faster operating speed. This study validates the developed numerical scale model against a field study using

The structural and anisotropic features of meso-structures consisting of a series of contacted particles hold the key to understanding the local shear failure and multi-scale mechanics of granular materials. However, the link between these meso-structures and their material deformation and failure characteristics have not yet been fully elucidated. By the means of Discrete Element Method (DEM), this

This paper investigates the kinematic response of floating piles under vertically propagating S-waves and proposes a rigorous solution for its vibration. By assuming the soil rod below the pile as a fictious soil pile, all motion fields in the half-space are obtained through a rigorous continuum elasto-dynamic model. The scattered wave and free-field wave field in the soil domain are derived from the

In slope reliability analysis, “local averaging” of the statistical soil parameters on the slope slip surface is the main factor influencing the results of the analysis. In this study, we analyzed the curvilinear local averaging of a 2-D random field by equation derivation based on random field theory and statistical analysis. By assuming a circular slip surface, the variance reduction due to curvilinear

Prediction of ground movement adjacent to an excavation is critically important, especially in urban areas, to prevent any potential damage of neighboring buildings. In the present study, a closed-form solution for prediction of excavation-induced ground settlement profile is proposed based on elastic displacement theory. Superposition method is employed to adapt the basic solution for translation

This paper established a coupled thermo-hydro-mechanical mechanism in view of the soil particle rearrangement for saturated/unsaturated soils under the framework of granular thermodynamics. This model avoids concepts such as the flow rule, yield function, dissipation potential function, and hardening criterion. The effects of the loading path and the soil structure are reflected by constructing a density

The ground-borne vibrations caused by surface and underground moving trains have been recognized as an important environmental issue. There are good reasons to develop prediction models to compute the ground-borne vibration from moving sources. Underground sub-surface structures linked with infrastructure construction are always present in cities like cavities, tunnels, pipes and subways. When these

Monopiles supporting offshore wind turbines are generally of relatively low slenderness ratio and are subjected to lateral loads that emanate from high above the seabed at an eccentricity that in most cases exceeds the embedded length of the pile. The rotational stiffness is a critical aspect of their design, owing to tight tolerances on the cumulative rotation that is permitted by industry guidelines

Particle shape plays a vital role in granular material behavior, but simulations with realistic particle shapes are uncommon due to significant computational demands of complex particle geometry representation. In this work, BLOKS3D, a polyhedral Discrete Element Method (DEM) and impulse-based DEM (iDEM) codes are parallelized to enable large-scale simulations with realistic particle shapes on readily

An approach is devised to determine the mechanical parameters of the microstructure of Dalian limestone rockfill material (DLRM) in triaxial compression DEM simulation. The parameters of the rockfill materials include the crushing strength parameters of the particles and the mechanical contact model parameters (mesoscopic parameters). The crushing strength parameters of the particles in the DEM simulation

The discrete element method (DEM) has been used to investigate the mechanical and failure behavior and the associated micro-cracking process of mudstone under the hollow cylinder torsional test by using a commercial DEM code PFC3D. Micro-parameters of the numerical model were first calibrated to the experimental results of the uniaxial compression tests and the uniaxial tensile tests. Based on the

In underground construction works, uncertainties and insufficient information about the underground environment lead to inaccurate predictions of soil-structure interactions. Supported excavations are often over-designed, which underscores a significant potential for cost optimization. However, the uncertainties exist, and the traditional design process does not allow for leaner designs at the start

Evaluating the bearing capacity of footing near slopes is typically performed under two-dimensional conditions. However, rectangular footings, particularly with footing aspect ratios approaching unity do not adhere to the assumption of plane-strain conditions. In this study, the scale effects of rectangular footings near slopes are investigated by using upper- and lower-bound finite element limit analysis

The determination of the incident angle of an earthquake is one of the critical research issues in modeling the seismic input mechanism at a dam site and it is also for geological exploration. At present, the incident angle calculation methods mostly rely on accurate geological models, complex theoretical formulations, and complicated procedures. To this end, an incident angle estimation method using

In order to obtain a better understanding of the load transfer mechanism of open-ended tubular piles driven into weak rocks, numerical analysis is conducted to study the internal and external shaft frictions, base resistance and the stress distribution pattern in the surrounding rock mass. Meanwhile, since pile shoes are often applied when driving to the rock layer, a common inner pile shoe attached

Analysis of tunnel-support system stability with uncertain rock mass properties is conducted in this paper. A horseshoe shaped tunnel driven in weak rock mass is analyzed through deterministic, random variable and random field approaches. Performance of the tunnel in probabilistic analysis was assessed by defining three limit states which ensure that tunnel convergence remained below a safe threshold

Rockburst is one of the severe geotechnical problems that may occur while tunnelling under high in-situ stresses. Despite numerous studies in the relevant literature, the evaluation and prediction of the rockburst still remain a common challenge worldwide. In this paper, a self-developed combined finite-discrete element method (FDEM) is used to numerically investigate the rockbursts in deep tunnelling

Bimsoils are mixtures of large geotechnically significant competent blocks embedded in a weaker soil matrix. Conventional design approaches usually account for the matrix strength characteristics, while empirical approaches use the volumetric block proportion (VBP) to modify matrix strength considering the presence of blocks. This article outlines a numerical approach to study the 2D bearing capacity

This paper advances a framework for evaluating mesh sensitivity in numerical models of systems involving strain-weakening materials, and demonstrates its application in the case study of the failure at the Mount Polley TSF in Canada. Numerical studies are combined with analytical arguments and physical evidence to establish that this failure was caused in part by the localisation of strain in a shear

An isotach elastoplastic constitutive model devised by Yang et al. (2016) and referred to as the Hunter Clay (HC) model attempts to capture a number of key behaviours of soft soils within a critical state framework, namely destructuration, fabric anisotropy and rate dependency, the latter often manifesting in creep settlement. Finite element implementation of the HC model is a useful means by which

The prediction of slope stability is difficult due to the spatial variability of soil parameters and measurement errors from core samples. This study proposed a Bayesian updating framework that based on the random finite element model (RFEM) method. The proposed approach was applied in a field excavation slope project. The field data of a soil slope with anti-slide bored piles under four-stage excavations

Cutting damages caused by frost action seriously threaten the safe operation of railways in cold regions. This paper uses worth of monitoring data to examine the temperature, unfrozen water, and deformation behaviors of a new High-speed Railway (HSR) anti-frost cutting bed in a deep seasonally frozen ground region. A frost numerical model is established to study the effectiveness of the anti-frost

The estimation of the deformation modulus of a rock mass is a fundamental factor in the design of civil works such as tunnels and dams. However, it is one of the parameters that entails highest difficulty when evaluating the rock mass. In this paper, a new analytical model is presented to assess rock mass deformability, with the aim of improving the estimation of the properties and their implementation

Extrusion damage in the concrete face was widely observed in high concrete-faced rockfill dams in the last two decades. However, the accurate estimation of the concrete stress remains a great challenge. In this paper, a thermo-mechanical coupling method is presented to numerically evaluate the solar radiation effect on the concrete stress within the dual mortar finite element framework. The heat conduction

Discrete element simulations are performed to better understand the breakage of marble spheres upon oblique impact. The influence of the contact friction coefficient and impact angle on the impact-induced breakage is considered. A modelling method for oblique impact is proposed. Detailed parameter calibration and verification of the modelling method were performed. The oblique simulations show that

Considering the foundation stiffness, this paper presents a new theory for consolidation of the stone column reinforced ground with time-dependent drainage boundary. The differential settlement between the soil the and column is obtained by using an improved equal-strain assumption. And the drainage capacity at the top of column is described by a time-decaying exponential function. Based on the above

Modeling the branching behavior of dynamic brittle crack helps reveal dynamic mechanism of brittle geomaterial fragmentation induced by multi crack bifurcation. In this study, the correlation between crack propagation speed and separation strain rate of crack surfaces is derived theoretically and verified based on the Kalthoff plate impact test, showing a strong linear positive proportional relationship

A series of undrained tests on loose sand with different pre-shearing histories are conducted in three-dimensional discrete element method (DEM) simulations. The pre-shearing histories are simulated under drained conditions with different pre-shearing strain levels ranging from 0% to 1.57%. Two different pre-shearing history types (pre-shearing cycle and pure pre-shearing) are investigated and compared

Confining stress is a major consideration in the assessment of liquefaction resistance of granular soils. In this study, the influence of confining stress to cyclic liquefaction from micromechanical perspectives are explored using DEM simulations. Eight samples with different confining stresses and void ratios are prepared and subjected to undrained cyclic loading tests to reach initial liquefaction

This paper explores the influence of dynamic behaviour under earthquake loading and soil heterogeneity on the bearing capacity of the strip footing over a horizontal ground of cohesionless soil. A finite element lower bound limit analysis formulation with second-order conic optimisation is used for the analysis. Dynamic behaviour of seismic waves is incorporated using a modified pseudo-dynamic approach

This study presents a non-linear spring model for modelling the backfill grout consolidation behind shield tunnel lining. Two important parameters, i.e. the time-dependent grout pressure decay induced by consolidation and the grout-cake thickness, were derived through a non-linear spring model and continuity equation. The proposed non-linear spring model for backfill grout consolidation was validated

This paper presents a model for calculating the small-strain shear stiffness of saturated and unsaturated fine-grained soils as the product of a dimensionless stiffness index and four individual functions of the mean average skeleton stress, the over-consolidation ratio, the reference saturated void ratio and the degree of saturation. The main element of novelty of the model resides in the introduction

Consolidation deformation induced by low frequency cyclic loads was investigated by finite element analysis (FEA) and some available test data. Both one-dimensional (1D) consolidation and the consolidation of a prefabricated vertical drain (PVD) unit cell were considered. With theoretical reasoning and using the results of FEA, it has been established that the amount and the rate of consolidation deformation

This work analyses the effect of the change in the initial stiffness on the behaviour of two geotechnical structures performed on/in overconsolidated clays: an embankment built on Boston blue clay and a tunnel dug in London clay. The numerical predictions are performed with the MIT-E3 model, which reproduces the small strain nonlinearity and hysteretic stress–strain response observed in unload-reload

A reliable and efficient numerical model is required for predictions of convection-conduction behavior in fractured rock mass to obtain a better understanding of heat transfer processes within it. This study presents a composite element formulation that addresses the problem of heat transfer via fluid flow in fractured rock mass. The three-dimensional convection-conduction equation is converted to

This study investigates the coupled effect of the soil spatial variations and the disturbance of ground surface on the existing tunnel using random finite difference method (RFDM). The soil Young's modulus is highlighted and simulated with horizontally stratified anisotropic random field that is discretized by the Karhunen-Loeve expansion. The surface surcharge is characterized from the statistics

The study of rock fragmentation mechanism significantly contributes to the advancing speed of tunnel boring machines (TBMs). In this sense, numerous factors are shaping the rock fragmentation mechanism of their disc-cutters. Among them, rock structural parameters, such as joint inclination, orientation, spacing, etc., considerably impact cutting force as well as rock-cutting process. However, detailed