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Building Trust. Engineering Success.
Vertical Lined Barrier System: Case Study: Four Hills Landfill
Presented by Ryan L. Clay, E.I.T.
Senior Project Engineer
Sanborn, Head & Associates, Inc.
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Presentation Outline
1. History of vertical lined barriers
2. Case Study: Four Hills Landfill a. The dilemma
b. Initial solution
c. Constructability issues
d. Diagnosing the problem
e. Designing new solution
f. Constructing the barrier
3. Questions
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History: what and why?
http://www.dewindonepasstrenching.com/wp-content/uploads/2012/06/HDPE_Barrier_Walls.jpg
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http://www.ce.utexas.edu/prof/zornberg/pdfs/BC/Zornberg_Christopher_2007.pdf
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Uses at Landfills
http://www.ce.utexas.edu/prof/zornberg/pdfs/BC/Zornberg_Christopher_2007.pdf
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Bristol Landfill in Bristol, Virginia - The first abandoned open-pit quarry excavation to be lined and backfilled with municipal solid waste.
http://geosyntheticsmagazine.com/articles/0410_f1_backfill.html
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http://www.tensarinternational.com/Applications/Landfill-Construction/Landfill-Liner-Support#
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Case Study – Nashua, NH
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YOU
ARE
HERE
Four Hills Landfill – Nashua, NH
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Closed Unlined Landfill
Closed Unlined
C&D Landfill
Active Lined
Landfill
LFGTE Facility operated by
PPL Renewable Energy Compost
Facility
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The dilemma
Landfill was designed/constructed with liner system extending within a 500-foot setback to structures not owned by the City.
City sought a waiver but was denied.
Cannot place any MSW within 500-foot setback.
Plan needed to optimize airspace.
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Airspace
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Separation
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Initial Solution
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Discovered Problem
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Investigation
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Lateral deviation
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http://www.bloggs74.com/artwork/food-art/
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Now what?
What’s done is done. City decides it’s not cost effective to recover lost airspace.
How do we move forward?
Can we get back on track?
Goal = Limit future loss of airspace.
Need a new plan.
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Maybe there’s another way
City expresses frustration with constructing the soil wall.
City suggests a retaining wall.
New design must be:
a) Hydraulic barrier;
b) Equal to or less expensive than constructing soil wall; and
c) Safe and simple to construct.
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Building Blocks
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Cheap
Interlocking
Easy to transport
Design
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NON-WOVEN GEOTEXTILE
NON-WOVEN GEOTEXTILE
SMOOTH HDPE GEOMEMBRANE
Profile
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Stability – Scenario 1
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Stability – Scenario 2
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Design Recommendation
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Construction
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Questions?
Thank you!
Ryan L Clay, E.I.T
Senior Project Engineer
Sanborn, Head & Associates, Inc.
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