Research Topics

Earthquakes can have devastating effects on communities, families, and societies as a whole.  In the interest of saving lives and developing sustainable and resilient infrastructure, scientists and engineers are faced with the challenge of developing methods by which seismic hazards can be understood, quantified, and incorporated into seismic design.  Jim's primary area of research focuses upon the prediction of earthquake-induced ground motion, an important component of any seismic hazard analysis.  With a greater understanding of the level of ground motion expected during earthquakes, engineers will be better able to design earthquake-resistant structures, and ultimately improve our sustainability by reducing the loss of life and property during earthquakes.

Jim's research in earthquake engineering has focused on the statistical and theoretical modeling involved in site response analyses and ground-motion prediction equations, and involves a balance between data-driven statistics and attention to the underlying physics of the models.  Across his projects, his research philosophy has been to apply rigorous statistical methods upon large datasets, ultimately working towards improving models for predicting earthquake-induced ground motion.  A secondary research interest of Jim's is engineering education, particularly on undergraduate geotechnical engineering courses, and he has been involved in multiple projects in this realm.  Please visit the Publications page or his Google Scholar profile for further details on his work.

Evaluation and improvement of site response models

Site response analyses are used to estimate site-specific ground motions, as a function of the properties of the soil profile and the input motion at the base of the soil profile.  These analyses attempt to capture the influence of near-surface geologic materials on seismic waves as they propagate from depth to the ground surface.  Despite their broad usage in engineering practice, site response models are burdened with significant uncertainties.  Jim has undertaken a number of projects involving ground motions from the data-rich Kiban-Kyoshin (KiK-net) network of vertical seismometer arrays in Japan.  His work has sought to identify which parameters offer the greatest contributions to site response prediction uncertainty, to compare and quantify uncertainties in various site response models and modeling assumptions, and to develop recommendations for the improvement of site response modeling.  More locally, Jim has been involved in assessment of site response in the Boston basin, and the unique seismic hazards associated with shallow sedimentary basins.

Ground-motion prediction equations

A fundamental step in any seismic hazard analysis is the quantification of the expected levels of ground motions for potential earthquakes, as well as the uncertainties in the estimates.  The expected level of ground motion may be estimated by a ground-motion prediction equation (GMPE), which is a semi-empirical model that predicts the ground motion at a given location as a function of earthquake magnitude, distance from the earthquake source, site characteristics, and other variables.  Compared to site response models (which are more site-specific in nature), GMPEs offer predictions that can be applied over broader areas.  Using a range of statistical methodologies, Jim developed a validation framework for GMPEs, and used this approach to quantify the prediction accuracies of models released as part of the Next Generation Attenuation of Ground Motions (NGA-West) project.  He also developed a methodology for estimating unknown source, path, and site parameters in GMPEs, with the intent of making these models more accessible for engineering practitioners.

Characterization of shear-wave velocity of soils for assessment of natural hazards

The amount of earthquake-induced ground motion at a site is largely governed by the properties of near-surface geologic materials, especially shear-wave velocity, which is an important input parameter for both site response analyses and GMPEs.  Jim has been involved in the application and assessment of surface-wave field testing methods to measure the dynamic behavior of near-surface soils.  The goals of these projects have been to evaluate the uncertainty and predictive capabilities of alternative soil field testing methods, as well as to quantify the spatial correlation structure of shear-wave velocity.

Geotechnical engineering education

As a professor at a predominantly undergraduate institution, Jim is deeply committed to undergraduate engineering education and methods by which student learning can be enhanced.  His projects in the realm of geotechnical engineering education include: (1) the usage of pre- and post-course knowledge surveys to assess gains in student learning, (2) incorporation of natural disasters into the undergraduate civil engineering curriculum, and (3) the development and improvement of educational/research software for geotechnical engineering and earthquake engineering. Jim’s projects to develop free and open-source software have resulted in a number of products available for usage in the community, and may be accessed on the Software page.