19/04/23 geo1.0

LimitState:GEOLimitState:GEOCase StudyCase Study

Colin Smith MA(Cantab) PhD

Director & LimitState:GEO Product Manager, LimitState Ltd

19/04/23 geo1.0

Introduction

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

Problem specification• An existing embankment is to be widened• A stem wall is to be constructed and backfilled with granular material• The widened embankment is to take additional loading. • How wide (B) should the stem wall be?

5m

B

Φ = 27º, γ = 18kN/m3

Φ = 34º, γ = 18kN/m3

10kN/m2 10kN/m245kN/m2

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

AnalysisRankine analysis using a virtual back is difficult due to the varied surface loads and the inclined soil interface

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

AnalysisCoulomb analysis more appropriate using a virtual back and a range of wedge angles

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

AnalysisInitial design might conservatively assume a frictionless virtual back to keep calculations simple

S

N

WW

R

P P

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

LimitState:GEO Analysis• Start with a DXF import of initial design

19/04/23 geo1.0

geo1.0:Analysis

Analysis

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

Analysis

• At this stage, LimitState:GEO was used to analyse the problem as described in the previous slides

(Hands on demo of software)

20/05/2008 LimitState:GEO launch & technology briefing - ICE London

Conclusions

• LimitState:GEO provides flexibility to rapidly consider a range of design scenarios

• It automatically selects the critical mechanism eliminating the need to separately consider e.g. sliding, bearing failure, global stability etc.

• Specific failure modes can be ‘forced’ if required

• Handles complex boundary conditions that would otherwise require simplifications and assumptions by conventional methods