Showing papers in "Computers and Geotechnics in 2019"

TL;DR: In this paper, the authors explored the effects of particle shape and content of fine particles on the shear behavior of sand-fines mixtures using a two-dimensional discrete element method and quantified the contributions of different contact types to the residual shear strength.

TL;DR: In this paper, an improved 3D rotational failure model based on the limit analysis method and an improved wedge-prism model were proposed to better assess the stability of tunnel faces in cohesion-frictional soils.

TL;DR: In this paper, a simple calculation scheme was proposed to estimate ground movements induced by horizontal jet grouting columns in fine-grained soils, considering the jetting parameters, soil properties, and volume of discharged spoil.

TL;DR: In this article, the authors describe the displacement and force behavior of a braced deep excavation under unsymmetrical surcharge effect and show that wall displacements reached maxima at depths slightly above the final excavation bottom due to the principal stress rotation resulting from the surcharge effects.

TL;DR: A simplified iterative algorithm for forward and/or inverse first-order reliability method (FORM) is presented and the geotechnical reliability-based designs of a strip footing and an earth slope are performed and some insights gained.

TL;DR: In this paper, a hybrid approach combining the EDFM (embedded discrete fracture model) and XFEM (extended finite element method) is proposed to investigate the effects of poroelastic properties and permeability on hydraulic fracturing in an anisotropic medium.

TL;DR: In this article, a finite element model is first calibrated based on the direct shear tests on a rough fracture to reproduce the uneven deformation of the fracture and then a Fluent Computational Fluid Dynamics analysis is subsequently used to illuminate flow characteristics in the fracture without and with asperity deformation.

TL;DR: In this paper, a 3D fractional elastoplastic model for soil is proposed based on the fractional derivative and covariant transformation, which can capture the strength and deformation behavior of soils under true 3D stress conditions.

TL;DR: In this paper, the authors investigated the occurrence and evolution of various slope failure modes during large deformation in spatially variable soils using Monte Carlo simulation combined with Limit Equilibrium Method (LEM) and Material Point Method (MPM).

TL;DR: In this article, an overview of grain-based modeling is presented to compare the advantages and limitations of different grain-mimicking methods, including intergranular and transgranular fracturing models and difficulties in parameter calibrations.

TL;DR: In this article, nonlinear finite element analyses for deep excavations in soft clay with different geometrical properties of the excavation, wall and soil properties were carried out to assess the basal heave factor of safety.

TL;DR: In this paper, a numerical parametric study is conducted to investigate the geometric effects of basement excavation on existing tunnels, and the most preferable excavation geometry is short-rectangular basement.

TL;DR: In this article, an analytical solution was proposed to investigate the response of an existing tunnel induced by new tunnel excavation underneath, where a Timoshenko beam lying on a Kerr foundation was adopted to model the existing tunnel subjected to ground disturbance induced by tunnel excavation.

TL;DR: In this paper, a grain-based distinct element model (GBM) was used to investigate the influence of grain size on the fracturing response of pre-cracked granite, and a cohesive model was developed and implemented in distinct element codes to mimic the elastic and softening response of the intra-grain contacts in GBM.

TL;DR: In this article, the lower bound finite element limit analysis in conjunction with semidefinite programming (SDP) is employed to investigate the stability of unlined square tunnels in Hoek-Brown (HB) material.

TL;DR: In this article, a 3D coupled Smoothed Particle Hydrodynamics (SPH) and Finite Element Method (FEM) model was developed to investigate the extent of damage zone and fracture patterns in rock due to blasting.

TL;DR: In this article, a new 3D collapse mechanism was proposed to investigate the face stability of a shallow tunnel embedded in the saturated and multi-layered soils with short-term condition.

TL;DR: A node-based explicit smoothed particle finite element method (eSPFEM) that uses a strain smoothing technique to avoid volumetric locking effects that are characteristic of low-order elements when the medium is incompressible is presented.

TL;DR: In this paper, a unified model for clays and sands, referred to as CSUH model, is proposed, which is based on the unified hardening (UH) model.

TL;DR: The methods provided in this research drastically reduce computational processing time, allowing simulations previously considered too computationally expensive for MCM analysis to be simulated without obstacle.

TL;DR: In this paper, the authors add the recent advances in particle shape representation, particle breakage modeling, and fragmental particle size and shape acquisition to the combined finite and discrete element method (FDEM).

TL;DR: In this paper, the interparticle tangential force displacement behavior of a broad range of granular materials was investigated using a custom-built micromechanical loading apparatus and the emphasis of the work was placed on the microslip displacement.

TL;DR: In this article, the bearing capacity of spatially varying soil in the presence of non-stationary feature of undrained shear strength is investigated, and Monte Carlo Simulations are carried out to evaluate the statistical characteristics of the resulted bearing capacity, followed by a detailed discussion on the effects of COV, strength gradient parameter, distribution type and vertical autocorrelation length.

TL;DR: In this paper, a generalized interpolation material point method numerical simulation of the Sainte Monique landslide is presented, using a strain-rate dependent Tresca constitutive model, extended with strain softening behaviour for structured clays.

TL;DR: In this article, a numerical procedure about nonlinear flow in 3D discrete fracture networks was developed by solving the Reynolds equation and Forchheimer equation using the Galerkin method.

TL;DR: In this article, the face stability of plane strain tunnel heading in anisotropic and non-homogeneous clays is investigated by the LB finite element limit analysis (FELA) with second-order cone programming (SOCP).

TL;DR: In this article, a four-constituent continuum finite difference model for suffusion has been extended through the self-filtration process, and a probabilistic study using the Monte Carlo method was conducted to analyze the effect of the variance, the spatial correlation length, and the cross correlation of the randomly distributed initial porosity and fines content on the eroded mass and on the evolution of the hydraulic conductivity under 1D and 2D conditions.

TL;DR: In this paper, both 2D and 3D finite element analyses were carried out to examine the strut forces for braced excavations in granular soils, based on the numerical results as well as the field measurements from a number of reported case histories, empirical charts have been proposed to determine strut loads for deep excavations with medium rigid walls.

TL;DR: In this paper, a probabilistic stability analysis of an embankment dam taking into account soil spatial variabilities is presented, where the effective cohesion and friction angle of the backfill are modelled as two anisotropic cross-correlated lognormal random fields by using the Karhunen-Loeve Expansion.

TL;DR: In this article, a generalized yield criterion accounting for the cross-anisotropic undrained strength of clay is proposed and requires four input shear strengths in triaxial compression and extension, direct simple shear, and pressuremeter tests.