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Retaining Wall Asset Management Program

STEM Activity

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Hennepin County

When you hear “Hennepin County”, what do you think of?

Hennepin County

How to set your image in the placeholder

  • Right click image and select “format picture”
  • Select “Picture” tab
  • Select Crop from the drop down menu
  • Under Picture Position, use the Offset X and Offset Y to position your image within the frame
  • delete this when no longer needed

Click to edit Master title style

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Hennepin County

    • Hennepin County is comprised of 45 cities
    • Hennepin County's mission is to enhance the health, �safety and quality of life for residents and communities
    • Many functions of a county, here are a few:
      • Public Safety and Law
      • Health and Medical and Libraries
      • Recycling and waste
      • Municipal projects around the county
      • Transportation
        • County road system

Hennepin County

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Hennepin County �Public Works

    • Our county road system:
      • Manage current system
      • Plan future road and bridge �projects
      • Maintain/repair existing �infrastructure
        • Roadways
        • Bridges
        • Trails
        • Retaining Walls and �other supporting �infrastructure

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Hennepin County

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Retaining Walls

Why do we use Retaining Walls?

      • Hold back soil and other loads to reduce the amount of land needed to purchase for a construction project.
      • Support above ground features such as roads, steep slopes, buildings, and trails.
      • Stabilize slopes to prevent erosion and slope failure

Hennepin County

How to set your image in the placeholder

  • Right click image and select “format picture”
  • Select “Picture” tab
  • Select Crop from the drop down menu
  • Under Picture Position, use the Offset X and Offset Y to position your image within the frame
  • delete this when no longer needed

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Materials

Retaining walls are made with different types of materials. Material selection varies with each project site.

      • Concrete
      • Natural Stone
      • Steel
      • Timber

Hennepin County

How to set your image in the placeholder

  • Right click image and select “format picture”
  • Select “Picture” tab
  • Select Crop from the drop down menu
  • Under Picture Position, use the Offset X and Offset Y to position your image within the frame
  • delete this when no longer needed

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Advantages + Disadvantages

We consider advantages and disadvantages when choosing materials:

Hennepin County

Cost

Strength

Durability

Loads

Environment

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How do you construct a retaining wall?

Hennepin County

Bottom Up

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Top Down

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Retaining Walls in the community

Hennepin County

Do you recognize this wall?

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Retaining Walls in the community

Hennepin County

Retaining Walls are categorized by “How They Act”

      • Gravity Walls
      • Piling Walls
      • Cantilever Walls
      • Anchored Walls

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Retaining Wall types

Hennepin County

    • Cantilever

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Retaining Wall failures

Hennepin County

Overturning – Horizontal Forces are greater than Vertical Forces keeping the wall upright

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Settlement/Slope Failure – Vertical Forces are greater than the strength of the soil underneath the wall.

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Types of failures we see

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Retaining Wall failures

Hennepin County

Washout – Inadequate drainage and/or waterproofing leads to material behind the wall being eroded away.

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Structural Failure – Horizontal Forces on wall greater than structural capacity of wall element causing it to break

Types of failures we see

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Questions

Hennepin County

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Activity

    • Divide into groups of 4-5
    • Follow the instructions provided on your worksheet
    • Class discussion for the last 10 minutes
    • Have fun!

Hennepin County