Research Interests

Current and recent topics

  • CPT-based characterization of intermediate and interbedded soils. In collaboration with Jason DeJong.
  • Constitutive modeling of liquefaction in sands and cyclic softening in clays/silts. In collaboration with Katerina Ziotopoulou.
  • Strength loss and strain-softening in contractive fine-grained soils under static and seismic loading.
  • Performance of embankments on spatially variable deposits of liquefiable sands and soft clays.
  • Effects of liquefaction-induced ground deformation on pile foundations. Includes collaborations with Bruce Kutter.
  • Dynamic properties of organic soils and site response in the Sacramento-San Joaquin Delta.
  • Soil liquefaction during earthquakes. In collaboration with I. M. Idriss.
  • NHERI Equipment Facility. In collaboration with Dan Wilson and Bruce Kutter.

PM4Sand: A sand plasticity model for earthquake engineering applications

  • The sand plasticity model, PM4Sand, by Boulanger and Ziotopoulou has been implemented as a dynamic link library (DLL) for use with the commercial program, FLAC (Itasca 2016). The manual and DLL are available here.
  • PM4Sand was developed for representing sands and other purely nonplastic granular soils in geotechnical earthquake engineering applications.

PM4Silt: A silt plasticity model for earthquake engineering applications

  • The silt plasticity model, PM4Silt, by Boulanger and Ziotopoulou has been implemented as a dynamic link library (DLL) for use with the commercial program, FLAC (Itasca 2016). The manual and DLL are available here.
  • PM4Silt was developed for representing saturated, plastic silts and clays that exhibit stress-history normalized behaviors in geotechnical earthquake engineering applications.

Penetration model and inverse filtering procedures

  • An inverse filtering procedure was developed by Boulanger and DeJong (2018) to correct CPT data for thin-layer and transition zone effects. A zip file containing the MatLab code with one example application to CPT data can be downloaded here.
  • The penetration filter model has also been used to estimate end bearing capacities of driven piles (Bittar et al 2020). A zip file containing the MatLab code for one example application to estimating pile end bearing capacities can be downloaded here (coming soon).

Dynamic centrifuge modeling and archived experimental data

  • Dynamic centrifuge modeling is used to study fundamental mechanisms and evaluate numerical analysis methodologies. The 9-m radius and 1-m radius geotechnical centrifuges at UC Davis are part of the Center for Geotechnical Modeling, which also serves as an equipment facility in the NSF-funded NHERI network.
  • Archived experimental data from centrifuge studies at our facility are publically available through the CGM (mostly pre 2005 data) and the NEES archives (for most recent data).

2013-08-20 13_07_14 CGM_centrifuge_2004

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