Geotechnical engineers help design structures that are either composed of soil or rock or are in contact with it. In essence, they engineer the interface between the natural and built environments. Research provides insight into the interaction and performance of structures with earth, such bearing failures, settlement damage, and failures due to emergent processes such as landslides and liquefaction. Scott Ashford, Matt Evans, Ben Mason, and Armin Stuedlein form the core of the geotechnical engineering research program in the School of Civil and Construction Engineering at OSU. Ben Leshchinsky is the College of Forestry liaison to CCE and the CE-FE advisor. Other affiliated faculty include Dan Gillens (geomatics), Michael Olsen (geomatics), Marv Pyles (Forest Engineering), Lee Schroeder (Emeritus), and Ted Vinson (Emeritus).
Professor Ashford’s research includes enhancing public safety and reducing potential economic loss worldwide from earthquake and coastal hazards through cross-disciplinary research in earthquake and coastal engineering, focusing on full-scale modeling of soil-foundation-structure interaction, seismic site response, coastal erosion, and slope stability.
Professor Evans’ research interests include granular mechanics, microstructure quantification, image analysis, numerical methods, unsaturated soil mechanics, and multiphysics behavior of soils, with applications to renewable energy, emergent phenomena (e.g., static and dynamic liquefaction), waste isolation, and sustainable infrastructure. His work is broadly multidisciplinary and has applications in fields such as materials handling, pharmaceuticals, biomechanical engineering, physics, and geology.
Professor Leshchinsky’s research interests include slope stability analysis and landslide prediction; use of soil reinforcement in earth retention, subgrade improvement, and slope stability; unpaved road behavior; vegetation-soil interaction; and management of water-sediment transport. His investigative approach involves an array of tools including numerical modeling, laboratory work and full-scale field testing. Professor Leshchinsky’s research is based in a variety of disciplines, broadly encompassing geotechnical engineering, water resources, agriculture and forestry.
Professor Mason’s research interests include soil-fluid-structure interaction, residual and momentary soil liquefaction, cyclic mobility of intermediate soils, seismic resiliency on a city-scale, cumulative damage caused by successive hazards, and the seismic response of Willamette Valley silt. He focuses on megathrust earthquakes created by the Cascadia Subduction Zone. Professor Mason leads the group’s Soil Dynamics laboratory, which contains cyclic triaxial and cyclic simple shear devices.
Professor Stuedlein’s primary research interests center on the full-scale behavior, performance, and reliability of geotechnical structures, including deep and shallow foundations, improved ground, and mechanically stabilized earth walls. Dr. Stuedlein recently completed research on the behavior of pipes and culverts installed by ramming, including the development of a comprehensive framework for the evaluation of pipe ramming performance. His approach combines the evaluation of instrumented geotechnical structures with lab-based soil characterization, numerical modeling, random field theory and geostatistics, and reliability theory to better understand and predict geotechnical performance.
The geotechnical faculty at OSU has a broad range of experience, including the effects of natural and human-made hazards, soil-structure interaction, fundamental soil behavior, and soil composite behavior. They provide opportunities for collaboration within CCE and with numerous other disciplines and specialties (e.g., Mechanical Engineering; Forest Engineering; the College of Earth, Ocean, and Atmospheric Sciences; Applied Mathematics; Statistics; Agricultural and Resource Economics; Microbiology).
Researchers at OSU understand the importance of spatiotemporal scales in geotechnical engineering – the fact that behavior at the particle level and the field level are inextricably linked. Accordingly, geotechnical research at OSU is performed across three spatial scales:
- Grain scale - Research includes computer simulations using very small elements, such as individual soil grains. It allows the discovery of fundamental mechanisms at the soil grain level that affect behavior at larger scales. Also, researchers can perform virtual experiments where actual experiments are impossible.
- Element scale - Laboratory experiments (i.e., element tests) and scale models (i.e., centrifuge and laminar box tests) to simulate soil/rock behavior are the predominant research tools at this scale. Specific experiments include quantifying the static and dynamic mechanical response of soils, thermal testing, and wave-based characterization of geomaterials.
- Field scale - This includes field testing for soil properties and of geostructures at full scale. Examples include: lateral load testing of pipe piles embedded in or near the crest of slopes, pipe ramming experiments, multi-channel analysis of surface waves (MASW) testing of native and densified soil, and multi-reinforcement strip pullout tests. The Geotechnical Engineering Field Research Site web page has more information about OSU research at this scale.