Foundations
Purpose
In order to properly design a highway or structure, we need to know the engineering characteristics of the soil in the area. The Foundations Unit provides surface investigations and geotechnical recommendations for transportation structures including bridges, retaining walls, large culverts, buildings, tower structures, light bases, high embankments, and embankments over soft soils.
When to use this subject
You will need the Foundations Unit on any project that includes:
- Bridges including:
- New bridge
- Bridge replacement
- Temporary bridges
- Bridge rehab and historic bridges if you anticipate foundations work/involvement
- Box culverts including:
- All box culverts with current or future bridge numbers
- Box culvert extensions
- Any culvert installed in a very deep trench
- Any culvert installed in poor soils
- Retaining walls and reinforced slopes including:
- Standard concrete cantilever walls
- Noise walls
- Modular block walls (greater than 4 feet in height)
- Mechanically stabilized earth (MSE) walls
- Sheet pile walls
- Visual barriers
- Soil nail walls
- Soldier pile walls
- Reinforced soil slopes (RSS) (1:1)
- High tension cable barrier (HTCB)
- Overhead sign structures
- High mast light towers
- Signal systems with long (greater than 45-foot) mast arms
- Embankments/roadways over poor soils, which require coordination with the District Soils Engineer to help identify areas with known poor soils or poor geologic conditions
- Pavement or slope distress including:
- Slope failures
- Landslides
- Sloughing
- Roadway distress
- Bumps/dips in the roadway
- Anything else that you anticipate needing foundations work/involvement
How this subject fits into the overall project development process
The Foundations Unit may be involved in:
- Emergency situations such as any catastrophic failure that may affect the State’s transportation system
- Scoping:
- Early identification of Geotechnical appurtenances that would affect cost, scope, and/or schedule; and
- Alternate Delivery (i.e.,Design-Build (DB), Construction Manager/General Contractor (CM/GC)
- Pre-construction:
- Design support (recommendations) for transportation infrastructure
- Plan review
- Construction:
- Geotechnical
- Instrumentation
- Inspection
- Post-construction:
- Monitoring
- Inspection
Organizations involved
- MnDOT:
- Foundations Unit
- Geology Unit
- Grading and Base Unit
- Bridge Office
- District Staff
- Project Managers
- Design Engineers
- Resident Engineers
- District Materials and Soils Engineers
- FHWA
- Minnesota Department of Health (MDH)
- Municipalities and Counties