Research Experiences for Undergraduates (REU), NSF NHERI 2024: Dynamic Characterization of Portland Soil Using Resonant Column Torsional Shear Testing

This research project focuses on the dynamic properties of soil from Portland Airport under various stress conditions using a Stokoe-type Resonant Column Testing System (RCTS). The primary objective of the study is to analyze the shear wave velocity (Vs) and stiffness of sand samples under different pressures, both normally consolidated (NC) and overconsolidated (OC), to understand their behavior in response to varying stress conditions. The project involves detailed experimentation, data collection, and analysis to observe changes in sand properties, especially when subjected to increasing and then decreasing pressures.

The data generated from this project can be reused in multiple ways. For example, it can be employed in further studies comparing the behavior of different soil types under similar conditions or in simulations to predict the response of soils in various geotechnical engineering applications. Moreover, the data can be utilized to refine existing models of soil behavior, contribute to developing new predictive tools for earthquake engineering, or aid in designing foundations and other structures in regions prone to seismic activity.

This project is unique due to its comprehensive approach to understanding the dynamic properties of sand under both normal and overconsolidated states. The use of a Stokoe-type RCTS provides high-resolution data, making it possible to capture subtle variations in the material's behavior. Additionally, the project stands out because of its focus on both increasing and decreasing pressure conditions, which is not commonly addressed in typical soil mechanics studies. This dual approach offers a more holistic view of soil behavior, particularly under cyclic loading conditions, which is critical for understanding and predicting soil performance in real-world scenarios.

The primary audience for this research includes geotechnical engineers, researchers in soil mechanics, civil engineers involved in foundation design, and earthquake engineering professionals. Additionally, the findings from this project would be valuable to academic institutions, students studying geotechnical engineering, and professionals involved in infrastructure development in seismically active regions.