Kansai International Airport (Phase-I) Foundation Case Study

ByRajul Teredesai

CE 5333-Foundation EngineeringSpring 2005

Overview

Kansai International Airport (KIA)

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

Kansai Airport Aerial View

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

Bore Hole Locations

Subsurface of the Kansai Airport Foundation

Seawall Construction

Up to 40 ft. above sea level Tripod blocks on seaward side for

dissipation of wave energy

Seawall After Completion

Seawall Construction

Mechanism of Sand Drains

Advantage of Sand Drains

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

Application of One Million Sand Drain at KIA

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

KIA Terminal Building

Architect: Renzo Piano

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

Settlement Calculations Consolidation Settlement:

Time Rate of Consolidation (Terzaghi 1925):

'

'log

1,vo

vo

o

cultc e

CH

2

2

z

uc

t

u ev

e

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%

Incomplete Consolidation

Underestimation of Excess Pore Water Pressure

Airport Started

Settlement Continued

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

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

References

A report by Justin Phalen, UC-Davis, 2002

The official website of KIA http://www.kald.co.jp/eindexframe.html

Questions?