About People

Stephen Semmens

Stephen Semmens, PhD

Geotechnical Staff

Stephen Semmens is experienced in geological engineering including field practices, design, research, and teaching. He is experienced in a range of disciplines across geology, engineering, and GIS. Stephen’s technical experience includes geologic mapping, rock mass and soil characterization, acquisition and interpretation of subsurface data, soil and rock mechanics, performance and review of geotechnical engineering analysis for soil and rock slopes, and laboratory testing. He also possesses a strong knowledge of backwards erosion piping along levees through his PhD research.

Stephen has experience in construction observation and geotechnical analysis for soil and rock slopes, shallow foundations, lateral earth pressures, settlement, and bearing capacity. He also has extensive practical GIS experience. Stephen has experience with data management, spatial analysis, design and preparation of map products, geoprocessing, and geostatistics. He is experienced with Leapfrog for 3D geologic modelling including database design, model construction, geologic interpretation, and numerical modelling. Additional competencies include Rapid Mass Movements (RAMMS) Debris Flow, SlopeW, and QGIS. Stephen also has a range of technical writing and data analytics experience including Python and Matlab coding.


  • PhD, Geological Engineering, Colorado School of Mines, 2020
  • MS, Geological Engineering, Colorado School of Mines, 2016
  • BS, Geological Engineering, Colorado School of Mines, 2014


  • American Society of Civil Engineers (ASCE)
  • Association of Environmental & Engineering Geologists (AEG) 

Practice Area

Geotechnical Services

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