Brett E. Bradfield
Senior Geotechnical Consultant, Terracon

Mr. Bradfield is a senior geotechnical consultant with Terracon, and he facilitates technical review of technology sector projects across the U.S., along with Midwest region projects with deep foundations, ground improvement methods, earthwork complications, slope stability, dams and wind turbine foundations. He holds an M.S. in geotechnical engineering from Iowa State University and served as an instructor for Foundation Engineering at ISU from 2013 to 2015.

Ehssan Hoomaan
Turner Construction Company

Dr. Hoomaan is a geotechnical design specialist at Turner Construction company with 5 years of experience in the geo-structural field. He provides technical reviews of geotechnical engineering reports, design analyses and submittals, plans, and specifications with the goal of optimizing design, assessing and mitigating risk, and improving constructability in structural foundations; earth retention and excavation support systems; ground improvement methods; groundwater control and design-build and alternate project deliveries. He has a Ph.D. in structural engineering from the City University of New York and is an adjunct professor at the City University of New York.

Rick Fosse
Professor of Practice, University of Iowa College of Engineering

Rick Fosse is a licensed professional engineer and faculty member in the University of Iowa’s Department of Civil and Environmental Engineering.  He teaches a variety of classes focusing on design, project management, leadership, ethics, resilient infrastructure and emergency response. 
Prior to joining the University, Rick practiced engineering for 33 years, including 25 years as Iowa City’s Public Works Director and City Engineer.

Scott Mackiewicz
VP/Principal Engineer, Braun Intertec

Dr. Mackiewicz is currently a Principal Engineer focused on the transportation market out of the Braun Intertec Lenexa, Kansas office. He has 28 years of experience in evaluating geologic conditions and providing geotechnical engineering consultation on a variety of transportation and heavy rail projects throughout the United States. He has evaluated and provided geotechnical design information for railroad track structures, shallow and deep foundations, retaining wall systems, slope stability, settlement, ground improvement, intermodal pavement design, full scale foundation load testing and lime/cement/fly ash stabilization. He is a member of AREMA Committee 8, Structures and Foundations and is the Heavy Rail Market Leader for Braun Intertec.

Bryan Ripp
Senior Engineer, Braun Intertech Corporation

BS and MS in Geological Engineering from South Dakota School of Mines and Technology and Missouri University of Science and Technology, respectfully.  Consultant for almost 40 years. Licensed or Registered Professional Engineer in 15 states, including Iowa.  Licensed or Registered Professional Geologist in 4 states.

Dennis Sensenbrenner
Senior Geology Consultant, Terracon Consultants, Inc.

Dennis Sensenbrenner is Senior Geology Consultant for Terracon’s Iowa Offices having been the Des Moines Environmental Department Manager for 14 years.  He is a graduate of the University of Louisville with a BS in Geology, a Professional Geologist registered in Nebraska and a and an Iowa-Certified Groundwater Professional.

Liz Smith
Vice President, Senior Principal, Terracon Consultants, Inc.

Liz Smith has been working in transportation geotechnical engineering for over 30 years, primarily on design build projects. She has been with Terracon over 16 years in the alternate delivery sector. Her projects are  across the US, from California to Seattle to Missouri, Maine, Virginia, Texas, and New Mexico.

Timothy Stark
Professor of Civil Engineering, University of Illinois at Urbana-Champaign

Dr. Stark is a professor of civil engineering at the University of Illinois at Urbana-Champaign and has been conducting research and teaching on the static and seismic stability of natural and manmade slopes.  Dr. Stark has received a number of awards for his research, teaching, and service activities including recently: 2022-2023 Cross-USA Lecturer from American Society of Civil Engineers (ASCE); 2022 T.H. Wu Lecturer at The Ohio State University; 2019 George H. Norman Medal, ASCE; Best Paper in Geosynthetics International Journal, 2016; 2015 James M. Hoover Lecturers at Iowa State University; Thomas A. Middlebrooks Award, ASCE, 2013 and 1998.; and Walter L. Huber Research Prize, ASCE, 2000.