Geology and Rock

Purpose

The Geology Unit performs geologic investigations and provides recommendations and designs related to geology and rock, particularly (but not limited to):

Karst/sinkholes
Rock slopes, rock excavation, and rock fall management

When to use this subject

You will need to contact the Geology Unit if you have karst/sinkhole needs on your project. For these needs, the Geology Unit will work within project, maintenance, and emergency schedules to assess available karst-related information (mostly via desktop review using geographic information systems (GIS)-based resources), review prior project information, perform field, subsurface, and hydrogeologic investigations (drilling, geophysics, e.g.) to understand geologic/karst model and draft/review karst related language for environmental documents, material design recommendations, specifications/special provisions, and designs for stormwater best management practices (BMPs) (ponds) and karst mitigation systems.

For projects with rock slopes, rock excavation and rock fall management needs, the Geology Unit will work within project, maintenance, and emergency schedules to perform field and subsurface investigations, assess rock mass characteristics, perform rock strength testing and analysis, perform rock fall and catchment modeling, design rock slope and catchment system, recommend excavation method and vibration control measures, draft/review excavation related specifications/special provisions, draft/review rock slope related designs/specifications/special provisions and make recommendations where supplemental rock fall mitigation and rock slope stabilization measures are needed (scaling, barriers, anchors, fences, draperies, e.g.).

For specific process information, contact Jason Richter, Joe Hudak or Micah Holzbauer. Alternatively, see the other guidance in the Legal Authority and Guidance sections.

How this subject fits into the overall project development process

Contact the Geology Unit for karst/sinkhole needs:

During scoping/preliminary design IF the environmental documents require comments related to potential for encountering karst terrain/features in a project area
During design IF:

Ponding is proposed for the project in potentially active karst terrain
Karst is anticipated or has been historically troublesome in that control section

After construction IF karst features or sinkholes manifest on MnDOT property and pose risk to structures, groundwater quality, and the public

Contact the Geology Unit for needs related to rock slopes, rock excavation and rock fall management:

During design IF:

You anticipate rock excavation
You anticipate rock cuts/back-slopes in rock
An existing rock slope has a history of troublesome rockfall events necessitating re-design

After construction IF rock fall events create negative impacts and risks to public safety, pavements, structures, and drainage systems

Organizations involved

MnDOT:

Office of Materials and Road Research
- Geology Unit
- Foundations Unit
Maintenance Managers
Project Managers
District Design
District Construction
District Water Resources
Bridge Office

Minnesota Pollution Control Agency (MPCA)