Kansai International Airport (Phase-I) Foundation Case Study

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Kansai International Airport (Phase-I) Foundation
Case Study

• By
• Rajul Teredesai
• CE 5333-Foundation Engineering
• Spring 2005

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Overview
Kansai International Airport (KIA)
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Key Features

• Located on a biggest man-made island in Osaka
  Bay, Japan
• Constructed cost over 14 billion
• The island of 4 X 1 km, constructed in around 18m
  of water, entirely from landfill
• Project Started in 1986
• Opened for flights in 1996
• The ASCE named KIA the 2 civil engineering
  project of the 20th century, second only to the
  Panama Canal

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Kansai Airport Aerial View
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Construction of Airport
Stage Activity Time
I Subsurface Investigation 1 year
II Sea Wall Construction 2 years
III Landfilling 4 years
IV Terminal Construction 2 years
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Bore Hole Locations
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Subsurface of the Kansai Airport Foundation
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Seawall Construction

• Up to 40 ft. above sea level
• Tripod blocks on seaward side for dissipation of
  wave energy

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Seawall After Completion
Seawall Construction
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Mechanism of Sand Drains
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Advantage of Sand Drains

• The weight of the piled sand forces the water in
  the clay to move outward along the sand piles.

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Application of One Million Sand Drain at KIA
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Reclamation

• Three distinct grades of sand, gravel and rock
  from nearby mountains
• Four years and 750 million cubic feet of fill
• Transportation on
• Ground Conveyor
• Water Barges

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KIA Terminal Building

• Architect Renzo Piano

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Settlement Predictions

• Lack of experience with construction on deep
  deposit of diluvial clay
• Expected settlement 19 to 25 ft
• Actual settlement 27 ft (by the end of island
  construction in 1990)
• It continued at the rate of 2 in/month

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Settlement Calculations

• Consolidation Settlement
• Time Rate of Consolidation (Terzaghi 1925)

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What Went Wrong in Predictions?

• Un-conservative estimation of consolidation
  settlement
• Wrong estimate of the time required for
  completion of consolidation settlement
• Ineffectiveness of the sand drains in achieving
  the required success 100

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Incomplete Consolidation
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Underestimation of Excess Pore Water Pressure
Airport Started
Settlement Continued
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Coping With The Problem of Continued Settlement

• Basement of the terminal was lined with a quarter
  of a million tons of iron ore.
• Result Island sank faster than the building it
  is trying to hold
• Installation of hydraulic jacks under the colums
• Result No differential settlement between the
  columns of entire building

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Learning From Mistakes

• Using data actual settlement data obtained from
  1st phase of project
• Analysis of 400-m-deep boring exploration
• State-of-the-art soil test methods
• Expected Settlement 18 m
• http//www.kald.co.jp/eindexframe.html

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References

• A report by Justin Phalen, UC-Davis, 2002
• The official website of KIA http//www.kald.co.jp/
  eindexframe.html

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Questions?