A One-Day Short Course by Doctors Ross Boulanger and Katerina Ziotopoulou

PM4 Sand and Nonlinear Dynamic Modeling of Liquefaction during Earthquakes

Friday, October 27, 2017

Executive Inn, 4201 Lougheed Highway, Burnaby, B.C.


The one-day short course covers the constitutive model PM4Sand and its use in nonlinear dynamic analyses of liquefaction during earthquakes. The PM4Sand model is a stress-ratio controlled, critical-state compatible, bounding surface plasticity constitutive model developed by Boulanger and Ziotopoulou (2012 – 2016) for earthquake engineering applications. It is implemented as a user-defined dynamic link library for use in Itasca's FLAC program. 

The topics covered include: theoretical background of PM4Sand (formulation and implementation); calibration procedures for engineering applications (single element simulations of various loading paths; capabilities and limitations); hands-on calibration exercises for an engineering application; validation example with focus on recommended practices for evaluating and documenting results of nonlinear dynamic analyses; and general discussion of best practices and modeling details.  

The short course is geared toward participants already having some level of familiarity with nonlinear dynamic analyses, nonlinear constitutive models, soil liquefaction during earthquakes, and the computer program FLAC. Coverage of each topic will include a review of background information and underlying fundamentals, but the focus will be more on details and procedures important to using these numerical models in practice. Participants are expected to bring a laptop computer loaded with FLAC 8.0 (a trial version will be sufficient), with the PM4Sand Version 3 dynamic link library, and the calibration drivers for PM4Sand (https://pm4sand.engr.ucdavis.edu/) so they can participate in the example exercises. 

Course Outline:

  • 08:00 - Welcome and Introduction
  • 08:30 - Theoretical Background - Formulation & Implementation in FLAC
  • 09:30 - Break
  • 10:00 - Calibration for Practice (Part 1)
  • 11:00 - Hands-on Calibration Exercises (Part 1)
  • 12:00 - Lunch
  • 13:00 - Calibration for Practice (Part 2)
  • 14:00 - Hands-on Calibration Exercises (Part 2)


  • 14:30 - Break
  • 15:00 - Validation Example & Best Practices for NDAs
  • 16:30 - Discussion
  • 17:00 - Finish


Professor Ross W. Boulanger is the Director of the Center for Geotechnical Modeling in the Department of Civil and Environmental Engineering at the University of California, Davis. He received his PhD and MS degrees in Civil Engineering from the University of California at Berkeley, and his BASc degree in Civil Engineering from the University of British Columbia. His research and professional practice are primarily related to liquefaction and its remediation, seismic performance of dams and levees, and seismic soil-pile-structure interaction. His honors include the TK Hsieh Award from the Institution of Civil Engineers, the Ralph B. Peck Award, Norman Medal, Walter L. Huber Civil Engineering Research Prize, and Arthur Casagrande Professional Development Award from the American Society of Civil Engineers (ASCE), and election to the National Academy of Engineering in 2017. 

Katerina Ziotopoulou joined the Department of Civil and Environmental Engineering at University of California at Davis in August of 2016. Prior to this appointment, she was an Assistant Professor at the Charles E. Via Jr. Department of Civil and Environmental Engineering at Virginia Tech for two years. She received her PhD and MS degrees in Civil Engineering from the University of California at Davis, and her undergraduate Diploma degree in Civil Engineering from the National Technical University of Athens, Greece. Currently, her research focuses on the numerical simulation of ground failure due to liquefaction during earthquakes. Her goals are to: (a) improve our understanding of the response of liquefiable soil-structure systems, (b) perform reliable numerical simulations and deliver usable numerical simulation tools, and through these (c) facilitate advances in performance-based design across a range of foundation design and ground improvement methods.