Dr. Wittich will present “Seismic Hazard Estimates Based on Precariously Balanced Rocks”:
Reliable estimates of seismic hazard are essential for the development of resilient communities; however, estimates of rare, yet high intensity earthquakes are highly uncertain due to a lack of observations and recordings. As a result, seismic hazard analyses for critical structures, such as nuclear waste repositories, are typically based on extrapolations from earthquakes with more moderate return periods, which can lead to physically unrealistic earthquake scenarios. However, the existence of certain precariously balanced rocks can be used to deduce an upper bound ground motion, which precludes toppling of the balanced rock, over its lifetime. Given that the age of these formations is typically in the tens of thousands of years, this upper bound over its lifetime can be used to constrain seismic hazard for very rare earthquakes. In this work, a subset of precarious rock systems near the Elsinore Fault in southern California were studied with detailed geometric surveys and a robust numerical model for toppling predictions. The primary outcome will be improved estimates of seismic hazard for critical structures, which require an analysis of very infrequent earthquakes.

Dr. Jiong Hu will present “Implementing Problem-Based Learning (PBL) in a Concrete Problem Course”:
This presentation is about an action-research case study detailing the evolutionary changes in the implementation of the problem-based learning (PBL) method in an undergraduate concrete problem, diagnosis, and repair course. The course embodies an unique pedagogical challenge as students are not only required to imbibe specific technical content, but also develop the ability to solve technical workplace problems. PBL was implemented in this course as a student centered active learning pedagogy. The presentation details the design of the course, issues involved in teaching, and the strategies that were employed to resolve the issues. The evolution in the adaptation of PBL pedagogy and key components for success in the implementation of PBL in the engineering classroom will be presented.