February Dinner Meeting - Benjamin Turner, Ph.D., P.E., G.E., P.Eng.

Benjamin Turner, Ph.D., P.E., G.E., P.Eng. a senior engineer at Dan Brown and Associates, will present at our February Dinner Meeting at the MDT Headquarters in Helena. The topic of this meeting is "Foundation Design for Moving Ground".

Dr. Turner is a senior engineer for Dan Brown and Associates specializing in seismic design aspects of geo-structural systems including foundations, excavations, and slopes. He is a recognized leader on the topics of kinematic loading on foundations due to lateral spreading and combined kinematic-inertial loading. He is author of the deep foundations chapter and soil-structure interaction content in the forthcoming 2026 update to FHWA GEC 03,  “Seismic Analysis and Design of Transportation Geotechnical Features and Structural Foundations” and wrote the updated seismic content in the 2018 version of FHWA GEC 10 (Drilled Shafts). Dr. Turner holds BS and MS degrees in civil engineering from Cal Poly, San Luis Obispo, where he has also served as an adjunct lecturer for the CE graduate program, and a Ph.D. in geotechnical earthquake engineering with a minor in seismic structural reinforced concrete design from UCLA. He continues to remain actively involved in research projects related to deep foundations and earthquake engineering and serves on the Seismic and Lateral Loads and Drilled Shafts Committees of the Deep Foundations Institute.

Foundations are designed for loads and deformation of the structures they support. Some projects pose the additional design challenge of horizontally or vertically deforming ground, which induces loads into the foundations through a “bottom up” load path that differs significantly from standard design. Moving ground can arise from seismic loading or general slope instability. In seismic regions such as western Montana and much of the western US, lateral spreading is a commonplace controlling design feature for many types of projects.

Engineers face many practical challenges when attempting to implement lateral spreading and downdrag code provisions and guidelines for their projects, such as those by AASHTO and Caltrans. This presentation will focus on practical issues including (1) choosing method(s) to estimate lateral spreading ground displacement and dealing with the large uncertainty of these methods, (2) using 2D slope stability analysis and other numerical tools to assess seismic or nonseismic slope instability including foundation resistance, (3) capturing interaction of foundation and superstructure components in simplified equivalent-static analyses, and (4) designing for downdrag in the context of settlement and serviceability.

Check-in and social hour begins at 5:00 with soft drinks available (no alcohol). Food will start between 5:00 and 5:30, and the presentation will begin around 6:15.