Modelling the seismic performance of root-reinforced slopes using the Finite Element Method

Teng Liang, Jonathan Knappett (Lead / Corresponding author), Anthony Leung, Glyn Bengough

Research output: Contribution to journalArticle

Abstract

This paper investigates the seismic performance of rooted granular slopes using dynamic finite element analysis, validated against recently published centrifuge test data. The importance of selecting suitable strength parameters to represent soil response within a strain hardening constitutive model was demonstrated and the simulations suggested that any boundary effects introduced through the use of the Equivalent Shear Beam container in the centrifuge are negligible and can be represented by a semi-infinite lateral boundary condition. Using the validated model, a parametric study investigated the effects of different rooted soil properties on the performance of slopes of different heights. Vegetation was effective in reducing deformations at the crest of modest height slopes, though the benefit reduced as slope height or soil apparent cohesion increased. The effectiveness was significantly affected by the extent of the root system, but only moderately sensitive to root cohesion, and insensitive to stiffness or damping of the rooted soil. Plant species possessing deep and extensive root systems are therefore recommended for seismic stabilisation rather than those with the strongest roots. For modelling purposes, it is sufficient to be able to quantify only the strength of the rooted soil and its area of influence. The magnitude of improvement from vegetation in terms of decreasing seismic permanent slip was also found to be insensitive to the construction method used (i.e. compacted/uncompacted embankment or cutting) for drained granular slopes.
Original languageEnglish
JournalGéotechnique
Early online date11 Apr 2019
DOIs
Publication statusE-pub ahead of print - 11 Apr 2019

Fingerprint

finite element method
Soils
Finite element method
centrifuge
root system
cohesion
modeling
Centrifuges
soil
slope dynamics
construction method
vegetation
hardening
embankment
damping
Embankments
stiffness
soil property
stabilization
Constitutive models

Keywords

  • Slope stability
  • Earthquakes
  • Numerical modelling
  • Centrifuge modelling
  • Vegetation
  • Sands

Cite this

@article{c390d3f18ff94da4bd56f8389b828f20,
title = "Modelling the seismic performance of root-reinforced slopes using the Finite Element Method",
abstract = "This paper investigates the seismic performance of rooted granular slopes using dynamic finite element analysis, validated against recently published centrifuge test data. The importance of selecting suitable strength parameters to represent soil response within a strain hardening constitutive model was demonstrated and the simulations suggested that any boundary effects introduced through the use of the Equivalent Shear Beam container in the centrifuge are negligible and can be represented by a semi-infinite lateral boundary condition. Using the validated model, a parametric study investigated the effects of different rooted soil properties on the performance of slopes of different heights. Vegetation was effective in reducing deformations at the crest of modest height slopes, though the benefit reduced as slope height or soil apparent cohesion increased. The effectiveness was significantly affected by the extent of the root system, but only moderately sensitive to root cohesion, and insensitive to stiffness or damping of the rooted soil. Plant species possessing deep and extensive root systems are therefore recommended for seismic stabilisation rather than those with the strongest roots. For modelling purposes, it is sufficient to be able to quantify only the strength of the rooted soil and its area of influence. The magnitude of improvement from vegetation in terms of decreasing seismic permanent slip was also found to be insensitive to the construction method used (i.e. compacted/uncompacted embankment or cutting) for drained granular slopes.",
keywords = "Slope stability, Earthquakes, Numerical modelling, Centrifuge modelling, Vegetation, Sands",
author = "Teng Liang and Jonathan Knappett and Anthony Leung and Glyn Bengough",
year = "2019",
month = "4",
day = "11",
doi = "10.1680/jgeot.17.P.128",
language = "English",
journal = "Geotechnique",
issn = "0016-8505",
publisher = "Thomas Telford Ltd.",

}

TY - JOUR

T1 - Modelling the seismic performance of root-reinforced slopes using the Finite Element Method

AU - Liang, Teng

AU - Knappett, Jonathan

AU - Leung, Anthony

AU - Bengough, Glyn

PY - 2019/4/11

Y1 - 2019/4/11

N2 - This paper investigates the seismic performance of rooted granular slopes using dynamic finite element analysis, validated against recently published centrifuge test data. The importance of selecting suitable strength parameters to represent soil response within a strain hardening constitutive model was demonstrated and the simulations suggested that any boundary effects introduced through the use of the Equivalent Shear Beam container in the centrifuge are negligible and can be represented by a semi-infinite lateral boundary condition. Using the validated model, a parametric study investigated the effects of different rooted soil properties on the performance of slopes of different heights. Vegetation was effective in reducing deformations at the crest of modest height slopes, though the benefit reduced as slope height or soil apparent cohesion increased. The effectiveness was significantly affected by the extent of the root system, but only moderately sensitive to root cohesion, and insensitive to stiffness or damping of the rooted soil. Plant species possessing deep and extensive root systems are therefore recommended for seismic stabilisation rather than those with the strongest roots. For modelling purposes, it is sufficient to be able to quantify only the strength of the rooted soil and its area of influence. The magnitude of improvement from vegetation in terms of decreasing seismic permanent slip was also found to be insensitive to the construction method used (i.e. compacted/uncompacted embankment or cutting) for drained granular slopes.

AB - This paper investigates the seismic performance of rooted granular slopes using dynamic finite element analysis, validated against recently published centrifuge test data. The importance of selecting suitable strength parameters to represent soil response within a strain hardening constitutive model was demonstrated and the simulations suggested that any boundary effects introduced through the use of the Equivalent Shear Beam container in the centrifuge are negligible and can be represented by a semi-infinite lateral boundary condition. Using the validated model, a parametric study investigated the effects of different rooted soil properties on the performance of slopes of different heights. Vegetation was effective in reducing deformations at the crest of modest height slopes, though the benefit reduced as slope height or soil apparent cohesion increased. The effectiveness was significantly affected by the extent of the root system, but only moderately sensitive to root cohesion, and insensitive to stiffness or damping of the rooted soil. Plant species possessing deep and extensive root systems are therefore recommended for seismic stabilisation rather than those with the strongest roots. For modelling purposes, it is sufficient to be able to quantify only the strength of the rooted soil and its area of influence. The magnitude of improvement from vegetation in terms of decreasing seismic permanent slip was also found to be insensitive to the construction method used (i.e. compacted/uncompacted embankment or cutting) for drained granular slopes.

KW - Slope stability

KW - Earthquakes

KW - Numerical modelling

KW - Centrifuge modelling

KW - Vegetation

KW - Sands

U2 - 10.1680/jgeot.17.P.128

DO - 10.1680/jgeot.17.P.128

M3 - Article

JO - Geotechnique

JF - Geotechnique

SN - 0016-8505

ER -