During the design phase of a project, the Geotechnical Engineering Section investigates the geotechnical aspects of the general roadway alignment chosen for a particular area. Surface geology recognizance and mapping, drilling of the subsurface soil and bedrock information, and sampling the soil and bedrock for engineering properties are conducted. A recommendation is then made for an appropriate geotechnical and geological design. The Geotechnical Engineering Office provides the designer with a narrative report covering issues on the project and makes recommendations. These recommendations include cut and fill slope design, foundation recommendations, special notes and mitigation of problem areas. Technical drawings are also included.
The Geotechnical Engineering Section is often involved in construction related issues, including geotechnical inspection of footing condition, approval for bridges and retaining walls, wet or soft soil conditions encountered by a contractor, unstable cut slopes or potentially dangerous rock fall areas, encapsulation of acid producing rock, sinkholes that occur during construction activity, and problems with the construction of geotechnical related retaining walls (MSE walls, tieback walls, soil nail walls, pile lagging walls, etc.)
The Geotechnical Engineering office often provides to the TDOT Maintenance Division information to repair subsidence areas related to sinkholes, landslides and embankment failures.