Reinforced soil design using a two-part wedge mechanism: justification and evidence

Paul McCombie, Mike Dobie

Research output: Contribution to conferencePaper

Abstract

Design methods for reinforced soil structures are normally divided into: external stability (defines structure dimensions) and
internal stability (determines reinforcement layout). This paper examines a method of calculation which has been developed for the internal
stability check based on a simple two-part wedge mechanism. The wedges are defined by a first plane across the width of the reinforced soil
zone, and a second plane upwards through the retained backfill. Reinforcement intersected by the first wedge contributes to the equilibrium
of forces. A large family of two-part wedges is defined, and sufficient reinforcement must be provided to ensure that all can achieve equilibrium without overloading the reinforcement. Extensive experience of using this technique indicates that the critical two-part wedge in an efficiently designed structure will normally be defined by a line crossing the reinforced soil zone at about 45 degrees, then extending through the backfill at the Coulomb angle. If seismic inertia forces are added, then the angles of both wedges will become less steep. The two-part wedge mechanism is compared with more comprehensive stability analyses, as well as observed behaviour in shaking table tests on smallscale reinforced soil walls.

Conference

ConferenceXVI European Conference on Soil Mechanics and Geotechnical Engineering
CountryUK United Kingdom
CityEdinburgh
Period13/09/1517/09/15

Fingerprint

Reinforcement
Soils

Cite this

McCombie, P., & Dobie, M. (2015). Reinforced soil design using a two-part wedge mechanism: justification and evidence. 1409-1414. Paper presented at XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, UK United Kingdom. https://doi.org/10.1680/ecsmge.60678

Reinforced soil design using a two-part wedge mechanism : justification and evidence. / McCombie, Paul; Dobie, Mike.

2015. 1409-1414 Paper presented at XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, UK United Kingdom.

Research output: Contribution to conferencePaper

McCombie, P & Dobie, M 2015, 'Reinforced soil design using a two-part wedge mechanism: justification and evidence' Paper presented at XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, UK United Kingdom, 13/09/15 - 17/09/15, pp. 1409-1414. https://doi.org/10.1680/ecsmge.60678
McCombie P, Dobie M. Reinforced soil design using a two-part wedge mechanism: justification and evidence. 2015. Paper presented at XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, UK United Kingdom. https://doi.org/10.1680/ecsmge.60678
McCombie, Paul ; Dobie, Mike. / Reinforced soil design using a two-part wedge mechanism : justification and evidence. Paper presented at XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, UK United Kingdom.6 p.
@conference{023f2edf340c44048bd4619c10f16f01,
title = "Reinforced soil design using a two-part wedge mechanism: justification and evidence",
abstract = "Design methods for reinforced soil structures are normally divided into: external stability (defines structure dimensions) andinternal stability (determines reinforcement layout). This paper examines a method of calculation which has been developed for the internalstability check based on a simple two-part wedge mechanism. The wedges are defined by a first plane across the width of the reinforced soilzone, and a second plane upwards through the retained backfill. Reinforcement intersected by the first wedge contributes to the equilibriumof forces. A large family of two-part wedges is defined, and sufficient reinforcement must be provided to ensure that all can achieve equilibrium without overloading the reinforcement. Extensive experience of using this technique indicates that the critical two-part wedge in an efficiently designed structure will normally be defined by a line crossing the reinforced soil zone at about 45 degrees, then extending through the backfill at the Coulomb angle. If seismic inertia forces are added, then the angles of both wedges will become less steep. The two-part wedge mechanism is compared with more comprehensive stability analyses, as well as observed behaviour in shaking table tests on smallscale reinforced soil walls.",
author = "Paul McCombie and Mike Dobie",
year = "2015",
month = "9",
day = "13",
doi = "10.1680/ecsmge.60678",
language = "English",
pages = "1409--1414",
note = "XVI European Conference on Soil Mechanics and Geotechnical Engineering ; Conference date: 13-09-2015 Through 17-09-2015",

}

TY - CONF

T1 - Reinforced soil design using a two-part wedge mechanism

T2 - justification and evidence

AU - McCombie, Paul

AU - Dobie, Mike

PY - 2015/9/13

Y1 - 2015/9/13

N2 - Design methods for reinforced soil structures are normally divided into: external stability (defines structure dimensions) andinternal stability (determines reinforcement layout). This paper examines a method of calculation which has been developed for the internalstability check based on a simple two-part wedge mechanism. The wedges are defined by a first plane across the width of the reinforced soilzone, and a second plane upwards through the retained backfill. Reinforcement intersected by the first wedge contributes to the equilibriumof forces. A large family of two-part wedges is defined, and sufficient reinforcement must be provided to ensure that all can achieve equilibrium without overloading the reinforcement. Extensive experience of using this technique indicates that the critical two-part wedge in an efficiently designed structure will normally be defined by a line crossing the reinforced soil zone at about 45 degrees, then extending through the backfill at the Coulomb angle. If seismic inertia forces are added, then the angles of both wedges will become less steep. The two-part wedge mechanism is compared with more comprehensive stability analyses, as well as observed behaviour in shaking table tests on smallscale reinforced soil walls.

AB - Design methods for reinforced soil structures are normally divided into: external stability (defines structure dimensions) andinternal stability (determines reinforcement layout). This paper examines a method of calculation which has been developed for the internalstability check based on a simple two-part wedge mechanism. The wedges are defined by a first plane across the width of the reinforced soilzone, and a second plane upwards through the retained backfill. Reinforcement intersected by the first wedge contributes to the equilibriumof forces. A large family of two-part wedges is defined, and sufficient reinforcement must be provided to ensure that all can achieve equilibrium without overloading the reinforcement. Extensive experience of using this technique indicates that the critical two-part wedge in an efficiently designed structure will normally be defined by a line crossing the reinforced soil zone at about 45 degrees, then extending through the backfill at the Coulomb angle. If seismic inertia forces are added, then the angles of both wedges will become less steep. The two-part wedge mechanism is compared with more comprehensive stability analyses, as well as observed behaviour in shaking table tests on smallscale reinforced soil walls.

U2 - 10.1680/ecsmge.60678

DO - 10.1680/ecsmge.60678

M3 - Paper

SP - 1409

EP - 1414

ER -