PEER Research Project Highlight: "Advancing the Practice of Cyclic Softening Assessments of Silts and Clays"

September 29, 2021

The impact of a PEER funded research project "Advancing the Practice of Cyclic Softening Assessments of Silts and Clays" is highlighted below. The project Principal Investigator (PI) is Armin W. Stuedlein, Oregon State University.  The Research Team includes Ali Dadashiserej, Graduate Student.

Download the Research Project Highlight which includes the abstract (PDF)

Research Impact

The geotechnical profession continues to find the estimation of cyclic strength of transitional soils a challenge, with significant cost-consequences associated with improperly characterizing the seismic behavior. For example, ground improvements to mitigate liquefaction and the corresponding expense may be avoided or reduced if the cyclic behavior can be suitably characterized and quantified for those soils that are instead found to exhibit cyclic softening behavior. The development of the proposed strain-based cyclic resistance models and corresponding refinement of the simplified method will offer the profession with an improved methodology for understanding certain tradeoffs between hazard mitigation and the likelihood of deformation thresholds. Characterization of model accuracy and uncertainty will allow for future, seamless integration into a probabilistic framework (presently available for the liquefaction triggering of sands) and within a performance-based earthquake engineering (PBEE) methodology. Availability of the database underpinning this work to the public will serve to further advance research into the susceptibility, triggering, and consequences of cyclic softening.

Figure 1. GCTS direct simple shear device used to quantify the cyclic and post-cyclic responses of soil specimens (internal LVDT not shown).