Background on PM4Silt & PM4SiltR

  • The plasticity model for silt (PM4Silt) was developed for geotechnical earthquake engineering applications by Professors Ross W. Boulanger (homepage) and Katerina Ziotopoulou (homepage) at the University of California at Davis. 
    • PM4Silt is a stress-ratio controlled, critical state-based, bounding surface plasticity model for clays and plastic silts that has been implemented as a user defined dynamic link library for use with the programs FLAC and FLAC2D by Itasca (homepage). The model was developed and implemented to approximate stress-strain responses of specific importance to geotechnical earthquake engineering and cyclic softening problems.
  • PM4SiltR is a viscoplastic version of PM4Silt developed for static slope stability applications by Boulanger, Ziotopoulou, and Oathes.
    • PM4SiltR was developed and implemented to approximate strain-rate dependent shear strength, stress relaxation, and creep.
  • PM4Sand, which provided the framework upon which PM4Silt was built, is available (homepage) for modeling sand and other purely nonplastic granular soils in geotechnical earthquake engineering applications. 
  • This website provide access to the user manuals, dynamic link libraries, example files, and various reference sources for PM4Silt and PM4SiltR.
  • We appreciate hearing from users, so please do send us an email (rwboulanger at ucdavis.edu or kziotopoulou at ucdavis.edu) and let us know about your applications and experiences. 
Cyclic example
Example: single-element simulation of undrained, uniform cyclic stress loading in direct simple shear

 

Modulus example
Example: single-element simulation of undrained, strain controlled loading in direct simple shear