The importance of improving seismic hazard assessments and the performance of civil infrastructure during earthquakes is unequivocally large. At the core of my research program at NCSU, my team focuses on: (1) site effects on ground motions, (2) geotechnical seismic hazards, such as liquefaction and lateral spreading, (3) seismic hazard assessment, and (4) hazard-consistent ground motions for engineering design.
Site Effects on Ground Motions
Within our team, the investigation of the influence of local soil conditions on ground motions, known as site effects, includes the characterization of dynamic properties of soils, rocks and bio-cemented sands, numerical modeling of seismic wave propagation, and the evaluation of the associated aleatory variability and epistemic uncertainties. Recent efforts focus on investigating near-surface attenuation parameters, their relationship with shear strains in soils, and the physics behind scattering and anelastic attenuation of seismic waves in soils. In addition, we study the implications of assumptions in the numerical modeling of one-dimensional site response.
Graduate researchers: Ishika Chowdhury, Chunyang Ji, Cristina Lorenzo, Kyunguk Na
Collaborators: Dr. Luis Fabian Bonilla (IFSTTAR/IPGP), Dr. Celine Gelis (IRSN) , Dr. Brina Montoya (NCSU)
Geotechnical Seismic Hazards
The study of liquefaction and lateral spreading is motivated by the extensive impact to the built environment (and corresponding economic losses) caused by these geotechnical seismic hazards. My team investigates the performance of current predictive models of liquefaction-induced large ground deformations (i.e., lateral spreading) and the incorporation of relevant geomorphological controls into the next generation of lateral spreading models to reduce the variability in lateral displacements estimations.
Graduate Researchers: Nancy Ingabire-Abayo
Collaborators: Dr. Ellen Chamberlin (Bucknell University), Dr. Brina Montoya (NCSU)
Seismic Hazard Assessment
My team explores the practice of seismic hazard assessment with an emphasis on site-specific probabilistic seismic hazard analysis (PSHA). Accurately constraining site effects and their associated uncertainty constitutes one of the main requirements to invoke the partially nonergodic PSHA concept. My team integrates improvements in site response estimations to various aspects of seismic hazard analysis, from host-to-target adjustments, spatial correlations of ground motion intensity measures, to the next generation of ground motion models.
Graduate Researchers: Chunyang Ji, Cristina Lorenzo
Collaborators: Dr. Fabrice Cotton (GFZ), Dr. Dino Bindi, Dr. Marco Pilz
Hazard-consistent Ground Motions
We are currently studying the contribution of input motion selection procedures to uncertainty in ground motion intensity measures relevant to geotechnical earthquake engineering analyses, the effects of ground motion directionality in spectral matching and scaling techniques within the context of performance-based design, and the definition of design ground motions compatible with expected high-frequency content for eastern US.
Graduate Researchers: Ishika Chowdhury, Raj Thangappa, Sugandha Singh
Collaborators: Dr. James Kaklamanos (Merrimack College), Dr. Albert Kottke (PG&E), Dr. Mervyn Kowlasky (NCSU), Dr. Abhinav Gupta (NCSU)