Reinforced Earth Walls Accommodate Settlement in Alexandria, LA

115 Pages·2013·13.48 MB·English

Reinforced Earth Walls in Alexandria, La.
Accommodate Settlement

The safe way is the only way
September 2012
Early RECo History in the USA
• This wall was part of a
FHWA demonstration
Project which included
10 other projects.
• Most of the demonstration
projects were on difficult
Sites – such as this slide
Correction.
1st Reinforced Earth Wall in the United States (1971)
- Slide Correction – California
September 2012 2
Early RECo History in the USA
• Reinforced Earth released from “experimental” status

• Usage by DOT’s mushroomed

• Many 1,000s of structures
• Millions of sq ft of walls

• Most structures were more routine – non-difficult sites

• 15 years after the first RE wall was but in California, the
Louisiana DOTD planned to build I-49 from Shreveport to
Alexandria.

• Retaining walls were planned in the urban areas of Shreveport
and Alexandria.

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1986 - Louisiana DOTD I-49 Shreveport to Alexandria
Routine MSE Walls – no
Foundation issues
Difficult MSE Wall
Considering compressible soils
(Focus of Presentation)
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I-49 Shreveport – 581,000 SF of Reinforced Earth Walls
September 2012 5
I-49 Alexandria – Reinforced Earth Walls
Focus of Presentation will be on the Alexandria Wall.

Fact about the project

Compressible Soils consideration beneath the Reinforced Earth walls

 78,000 SF – Multiple Projects –

Opportunity for significant savings compared to the C.I.P. Walls

 24 FT Max. Height

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I-49 Alexandria – Cast-in-Place Wall Details
Original C.I.P. Wall
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I-49 Alexandria – Piling Layout
Original C.I.P. Wall
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I-49 Alexandria – Reinforced Earth Walls
Focus of Presentation will be on the Alexandria Wall.

Fact about the project

Compressible Soils consideration beneath the Reinforced Earth walls

 78,000 SF – Multiple Projects

Opportunity for significant savings compared to the C.I.P. Walls

 24 FT Max. Height

 LA DOTD elected to utilize the Flexibility of Reinforced Earth technology

 Specified Construction Staging with and without Wick Drains

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Flexibility of Reinforced Earth Walls
• First – Let look at the Flexibility of the Reinforced Earth wall
Soil & reinforcements can handle almost any settlement

Differential Settlement of facing panels governs - this is
the limiting constraint

 Allowable Total Settlement up to 30”

 For excessive settlement (total or differential), consider:
Vertical Slip Joint Covers
2-Stage Wall Technology

Why are RECo facing panels flexible?
It’s about the joints
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