Some techniques for finite element analysis of embankments on soft ground

1993 ◽  
Vol 30 (4) ◽  
pp. 710-719 ◽  
Author(s):  
J.C. Chai ◽  
D.T. Bergado
Keyword(s):  
Finite Element ◽  
Numerical Models ◽  
Relative Displacement ◽  
Technical Note ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Soft Ground ◽  
Element Analysis ◽  
Consolidation Process ◽  
Interface Elements

The accuracy of finite element results depends on the numerical models and the parameters used as well as the numerical techniques adopted. Three aspects of modelling the behavior of embankment on soft ground are discussed in this technical note: (i) simulating the actual construction process, (ii) modelling the soft ground permeability variation during the loading and consolidation process, and (iii) selecting proper soil–reinforcement interface properties according to the relative displacement pattern of the upper and lower interface elements placed between the soil and reinforcement in the case of a reinforced embankment. The significance of these factors on the performance of the embankment on soft ground is demonstrated by case studies. Key words : finite element method, loading, permeability, reinforced soil.

Stresses and deformations in a reinforced soil slope

1990 ◽  
Vol 27 (2) ◽  
pp. 224-232 ◽  
Author(s):  
R. J. Chalaturnyk ◽  
J. D. Scott ◽  
D. H. K. Chan ◽  
E. A. Richards
Keyword(s):  
Finite Element ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Maximum Load ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Soil Slope ◽  
Element Analysis ◽  
Reinforced Slope ◽  
Reinforcing Layer

Nonlinear finite element analyses were performed on a nonreinforced embankment and a polymeric reinforced embankment, with 1:1 side slopes, constructed on competent foundations. The nonreinforced and reinforced embankment analyses are compared to examine the influence of polymeric reinforcement within a soil slope. It is shown that significant reductions in the shearing, horizontal, and vertical strains within the slope occur because of the presence of the reinforcement.The finite element analysis of the reinforced embankment construction gives the magnitude and distribution of load within the reinforcement. For all embankment heights, the maximum reinforcement load did not occur in the lowest reinforcing layer but in the reinforcing layer placed 0.4H above the foundation, where H is the height of the slope. The displacement patterns and surface deformations of the nonreinforced and reinforced slopes are compared to show the marked reduction in slope movements resulting from the presence of the reinforcement.The location and shape of potential shear surfaces within the homogeneous reinforced slope are examined. The position of the maximum load in each reinforcing layer within the reinforced slope indicates that, for the example studied, a circular-shaped slip surface represents a probable failure mechanism within the slope. Key words: soil reinforcement, geotextiles, finite element, slope stability, geogrids, limit equilibrium, reinforced slope.

Finite element modeling of hexagonal wire reinforced embankment on soft clay

2000 ◽  
Vol 37 (6) ◽  
pp. 1209-1226 ◽  
Author(s):  
D T Bergado ◽  
C Teerawattanasuk ◽  
S Youwai ◽  
P Voottipruex
Keyword(s):  
Finite Element ◽  
Full Scale ◽  
Soil Reinforcement ◽  
Wire Mesh ◽  
Direct Shear ◽  
Full Scale Test ◽  
Element Analysis ◽  
Consolidation Process ◽  
Scale Test ◽  
Test Embankment

A full-scale test embankment was constructed on soft Bangkok clay using hexagonal wire mesh as reinforcement. This paper attempts to simulate the behavior of the full-scale test embankment using the finite element program PLAXIS. The agreement between the finite element results and the field data is quite good. The important considerations for simulating the behavior of the reinforced wall embankment were the method of applying the embankment loading during the construction process, the variation of soil permeability during the consolidation process, and the selection of the appropriate model and properties at the interface between the soil and reinforcement. The increased reinforcement stiffness tends to increase the reinforcement tension and increase the embankment forward rotation. The reinforcement tensions increased with the compression of the underlying soft foundation. The appropriate interface properties between the backfill soil and the hexagonal wire mesh reinforcement corresponding to the interaction mechanism at working stress conditions were dominated by the direct shear mechanism. The direct shear interaction coefficient of 0.9 was used.Key words: soil reinforcement, hexagonal wire mesh, finite element analysis, field embankment.

Analysis of membrane action in reinforced unpaved roads

1995 ◽  
Vol 32 (6) ◽  
pp. 946-956 ◽  
Author(s):  
H.J. Burd
Keyword(s):  
Finite Element ◽  
Soft Clay ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Single Application ◽  
Membrane Action ◽  
Element Analysis ◽  
Unpaved Roads ◽  
New Model ◽  
Design Procedures

Polymer grid or geotextile reinforcement may be used to improve the performance of reinforced fill layers placed on soft ground. This paper is concerned with the mechanics and design of reinforced unpaved roads built over soft clay, which is a particular application of this reinforced soil technique. A discussion is given of the mechanics of reinforced unpaved roads for the case of a single application of a plane strain, monotonic load, and the design procedures that are currently available for this type of structure are reviewed. A new analytical design model is proposed. This new model is based on a membrane reinforcement mechanism and is appropriate for cases where large surface deformations are acceptable. Results obtained using this new model are shown to compare well with data obtained from previously published laboratory tests. The use of a finite element method to study this type of structure is described, and the results of finite element analysis are used to discuss the accuracy of the proposed analytical model. Key words : soil reinforcement, unpaved roads, membrane, finite elements, reinforcement mechanisms, foundations.

Improved understanding of geogrid response to pullout loading: insights from three-dimensional finite-element analysis

2020 ◽  
Vol 57 (2) ◽  
pp. 277-293 ◽  
Author(s):  
Mahmoud G. Hussein ◽  
Mohamed A. Meguid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Interface Condition ◽  
Element Analysis ◽  
Analysis And Design ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Soil reinforcement has rapidly become one of the most common soil improvement techniques used in geotechnical engineering. Understanding the behavior of a geogrid under pullout loading is essential for the analysis and design of reinforced soil systems. The overall behavior of reinforced soils is generally dependent on the properties of the geogrid material, the backfill soil, and the interface condition. Modeling the three-dimensional aspects of soil–geogrid interaction under pullout loading condition is numerically challenging and requires special consideration of the different modes of resistance that contribute to the pullout capacity of the geogrid reinforcement. This study describes the results of a three-dimensional finite-element analysis that has been developed to investigate the behavior of a biaxial geogrid embedded in granular backfill material and subjected to pullout loading. The modeling approach considers the noncontinuous nature of the geogrid geometry and the elastoplastic response of the geogrid material. Model validation is performed by simulating laboratory-size pullout test and comparing the experimental data with the analytical as well as numerically calculated results. The detailed behavior of the geogrid and the surrounding backfill is investigated using the proposed numerical approach. Conclusions are made to highlight the suitability of this technique for analyzing similar soil–structure interaction problems.

3D Coupled Thermomechanical Finite Element Analysis of Ultrasonic Consolidation

2007 ◽  
Vol 539-543 ◽  
pp. 2651-2656 ◽  
Author(s):  
C.J. Huang ◽  
E. Ghassemieh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Stress Field ◽  
Ultrasonic Wave ◽  
Ultrasonic Vibration ◽  
Softening Effect ◽  
Element Analysis ◽  
Consolidation Process ◽  
Ultrasonic Consolidation

A 3-D coupled temperature-displacement finite element analysis is performed to study an ultrasonic consolidation process. Results show that ultrasonic wave is effective in causing deformation in aluminum foils. Ultrasonic vibration leads to an oscillating stress field. The oscillation of stress in substrate lags behind the ultrasonic vibration by about 0.1 cycle of ultrasonic wave. The upper foil, which is in contact with the substrate, has the most severe deformation. The substrate undergoes little deformation. Apparent material softening by ultrasonic wave, which is of great concern for decades, is successfully simulated. The higher the friction coefficient, the more obvious the apparent material softening effect.

scholarly journals An Improved Analytical Solution for Process-Induced Residual Stresses and Deformations in Flat Composite Laminates Considering Thermo-Viscoelastic Effects

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2506 ◽  
Author(s):  
Chao Liu ◽  
Yaoyao Shi
Keyword(s):  
Differential Equation ◽  
Finite Element ◽  
Analytical Solution ◽  
Residual Stresses ◽  
Composite Laminates ◽  
Composite Structures ◽  
Numerical Models ◽  
Element Analysis ◽  
Current Time ◽  
Viscoelastic Effects

Dimensional control can be a major concern in the processing of composite structures. Compared to numerical models based on finite element methods, the analytical method can provide a faster prediction of process-induced residual stresses and deformations with a certain level of accuracy. It can explain the underlying mechanisms. In this paper, an improved analytical solution is proposed to consider thermo-viscoelastic effects on residual stresses and deformations of flat composite laminates during curing. First, an incremental differential equation is derived to describe the viscoelastic behavior of composite materials during curing. Afterward, the analytical solution is developed to solve the differential equation by assuming the solution at the current time, which is a linear combination of the corresponding Laplace equation solutions of all time. Moreover, the analytical solution is extended to investigate cure behavior of multilayer composite laminates during manufacturing. Good agreement between the analytical solution results and the experimental and finite element analysis (FEA) results validates the accuracy and effectiveness of the proposed method. Furthermore, the mechanism generating residual stresses and deformations for unsymmetrical composite laminates is investigated based on the proposed analytical solution.

scholarly journals Evaluation of Anterior Cruciate Ligament Surgical Reconstruction Through Finite Element Analysis

2021 ◽  
Author(s):  
Konstantinos Risvas ◽  
Dimitar Stanev ◽  
Lefteris Benos ◽  
Konstantinos Filip ◽  
Dimitrios Tsaopoulos ◽  
...  
Keyword(s):  
Finite Element ◽  
Anterior Cruciate Ligament ◽  
Reference Model ◽  
Numerical Models ◽  
Cruciate Ligament ◽  
Surgical Techniques ◽  
Surgical Reconstruction ◽  
Modeling Framework ◽  
Element Analysis ◽  
Anterior Cruciate

Abstract Anterior Cruciate Ligament (ACL) tear is one of the most common knee injuries. The ACL reconstruction surgery aims to restore healthy knee function by replacing the injured ligament with a graft. Proper selection of the optimal surgery parameters is a complex task. To this end, we developed an automated modeling framework that accepts subject-specific geometries and produces finite element knee models incorporating different surgical techniques. Initially, we developed a reference model of the intact knee, validated with data provided by the OpenKnee project. This helped us evaluate the effectiveness of estimating ligament stiffness directly from MRI. Next, we performed a plethora of “what-if” simulations, comparing responses with the reference model. We found that a) increasing graft pretension and radius reduces relative knee displacement, b) the correlation of graft radius and tension should not be neglected, c) graft fixation angle of 20 degrees can reduce knee laxity, and d) single-versus double-bundle techniques demonstrate comparable performance in restraining knee translation. In most cases, these findings confirm reported values from comparative clinical studies. The numerical models are made publicly available, allowing for experimental reuse and lowering the barriers for meta-studies. The modeling approach proposed here can complement orthopedic surgeons in their decision-making.

Incorporation of Spinal Flexibility Measurements Into Finite Element Analysis

1990 ◽  
Vol 112 (4) ◽  
pp. 481-483 ◽  
Author(s):  
Mack G. Gardner-Morse ◽  
Jeffrey P. Laible ◽  
Ian A. F. Stokes
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stiffness Matrix ◽  
Beam Element ◽  
Technical Note ◽  
Element Analysis ◽  
Spinal Motion ◽  
Spinal Flexibility

This technical note demonstrates two methods of incorporating the experimental stiffness of spinal motion segments into a finite element analysis of the spine. The first method is to incorporate the experimental data directly as a stiffness matrix. The second method approximates the experimental data as a beam element.

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