Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20201

Automatic parameter determination for PLAXIS soil models

Dr. Ronald B. J. BrinkgreveBentley Systems, Inc.PhD, distinguished Scientist — GeotechnicalAssociate professor at TUDelft, Netherlands

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20202

Outline

• Introduction

• Vision

• Automatic Parameter Determination

• Conclusions

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20203

Introduction

Automation makes things easier...

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20204

Introduction

Automation makes things easier...

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20205

Introduction

Automation makes things easier...

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20206

Introduction

Automation makes things easier...

... and it mitigates the human factor!

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20207

My vision is:

Make complex things easy by automation

PLAXIS examples from the past:

• Making FEM accessible to geotechnical engineering practice

➢ Automatic load and time-stepping

➢ Enhanced mesh refinement

➢ Advanced, yet robust soil constitutive models with clear model parameters

➢ Simulation of soil lab tests, calibration of model parameters

Vision

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20208

All this starts from scientific background, but with focus on practical application, hence

from Research to Application

Collaboration with universities, research centres and industry:

➢ Delft University of Technology

➢ University of Graz, Trondheim, Grenoble, Oxford, Athens, MIT, Berkeley, ...

➢ Institutes: Norwegian Geotechnical Institute (Norway), BAW (D), Deltares (NL)

➢ Companies: W+B (NL), Fugro (NL), Baugrund Dresden (D), ...

Vision

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 20209

Previous and current work on automated parameter determination:

➢ Publication on HSsmall model parameters based on Relative Density only

➢ Parameter Guide 1.0: Too complex; black box; not the right time

➢ Publication in : several positive responses

➢ Publication in

➢ Publication in (in Dutch)

➢ Presentation at ECSMGE in Rejkjavik: if WE don't do it (together with our academic partners), competition will do it (and it will grow beyond our control)

➢ MSc projects at TUDelft: 1st student graduated; 2nd half way; 3rd about to start

➢ Collaboration with W+B, TUGraz, ...

Automatic Parameter Determination

Automation makes things easier...

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202010

• Users find it difficult to determine model parameters

• Limited soil data available in early stage of a project

➢ Most likely, only field test data (CPT, SPT)

• Promote the use of advanced soil models

• Improve consistency of input data

• Improve consistency (quality!) of results

• Improve workflow efficiency

(Schweiger, 2002)

Automatic Parameter Determination — Why?

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202011

• Starting from CPT data (source parameters qc, fs, Rf)

• CPT interpretation of layers > PLAXIS borehole

• Determine HSsmall model parameters for each layer

• Using chains of correlations

• Find paths from source parameters via intermediate parameters to model parameters

• Determine value based on multiple paths

• Create PLAXIS material data sets

Automatic Parameter Determination — Concept

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202012

Demo

Automatic Parameter Determination — Concept

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202013

Conditions:

• Transparency > verification, acceptance

➢ Correlations > references

➢ Paths > visualization

➢ Parameter values

• Adaptability > add new correlations, methods (also user-defined)

• Robustness

Automatic Parameter Determination — Conditions

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202014

• Search engine (multiple paths) > done

• Multi-layer extension (stress levels!) > almost done

• Dealing with uncertainties > current research

• Determine appropriate parameter value > current research

• Preventing circular paths (infinite loops)

• Covering all soil types (organic soils!)

• Verification and validation

Automatic Parameter Determination — Challenges

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202015

Conclusions

• Automation makes things easier...

• Automation requires research, with focus on practical application

• Automation provides a competitive advantage

• To automate numerical analysis, it is essential for us to understand

• The (theoretical/scientific) backgrounds

• The engineering practice

Dr. Ronald B.J. Brinkgreve, Bentley Systems, Inc.

XIII Russian PLAXIS User Meeting | October, 202016

Conclusions

Automatic parameter determination:

• Based on field test data

• Promotes the use of advanced soil models

• Improves the quality of results

• Transparent and adaptable

• Helps solving your geotechnical cases efficiently