1. Kansai International Airport (Phase-I) Foundation Case StudyBy
Rajul Teredesai
CE 5333-Foundation Engineering
Spring 2005

2. Overview
Kansai International Airport (KIA)

3. 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

4. Kansai Airport Aerial View

5. Construction of Airport
Stage
Activity
Time I
Subsurface Investigation
1 year II
Sea Wall Construction
2 years
III
Landfilling
4 years IV
Terminal Construction

6. Bore Hole Locations

7. Subsurface of the Kansai Airport Foundation

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

9. Seawall After Completion
Seawall Construction

10. Mechanism of Sand Drains

11. Advantage of Sand Drains
The weight of the piled sand forces the water in the clay to move outward along the sand piles.

12. Application of One Million Sand Drain at KIA

13. 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

14. KIA Terminal Building
Architect: Renzo Piano

15. 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

16. Settlement Calculations
Consolidation Settlement:
Time Rate of Consolidation (Terzaghi 1925):

17. 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%

18. Incomplete Consolidation

19. Underestimation of Excess Pore Water Pressure
Airport Started
Settlement Continued

20. 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

21. 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

22. References A report by Justin Phalen, UC-Davis, 2002
The official website of KIA

23. Questions?