1. Mantas Enceris Athar Aziz
The Settlement of Kansai International Airport
Mantas Enceris Athar Aziz

2. INTRODUCTION
Kansai International Airport is located on an artificial island in the middle of Osaka Bay, Japan
The island is 4km long and 1km wide
Construction started in 1987
The sea wall was finished in 1989
In km bridge was completed
to connect the island to the main land
The airport opened in 1994

3. FORMATION OF THE SEA BED
The undersea floor bed of Kansai International Airport is made up of sand and clay. The thickness of the layers increases as the sea deepens
At the top of the formation the Holocene clay layer is approximately 20m in thickness
The Holocene layer accumulated in the fourth Alluvial epoch 10,000 years ago to the present day always laying under the sea
The Pleistocene layer consists of alternating layers of hard clay
and gravel goes deep to hundreds of meters
The Pleistocene layer can be divided into upper and lower parts
The Pleistocene layer accumulated in the fourth Pleistocene epoch from approximately 2 million years ago to 10,000 years ago

4. THE SOIL OF THE SEA BED
Clay layers accumulate on the seabed when the soil is under the sea
Sand layers accumulate on the soil when the water level decreases and the soil emerges from the water

5. WHY SETTLEMENT OCCURS
Approximately 70 percent of the soft alluvial clay contains water
Even the hard Pleistocene clay contains 40 percent of water
The weight of the artificial island presses the water out of the clay layers of the seabed, and causes the land to settle

6. CHARACTERISTICS OF THE SETTLEMENT OF THE HOLOCENE LAYER
The settlement of the Holocene clay layer beneath the airport was stopped by artificially speeding up the process in less than a year
The Sand Drain method was the solution to let the water out of the clay layer as fast as possible
A million of sand drains (20m long and 40cm in diameter) were driven at 2.5m intervals into the clay layer under the island

7. CHARACTERISTICS OF THE SETTLEMENT OF THE HOLOCENE LAYER
The settlement data of the Holocene clay layer shows that the settlement ended in less that a year after the reclamation land was loaded on and the Sand Drain method was employed
The airport reclamation land has sunk very little since the alluvial settlement ended. Now settlement has completely ended

8. CHARACTERISTICS OF THE SETTLEMENT OF THE PLEISTOCENE LAYER
The long-lasting, and ongoing settlement under the airport since its opening is still taking place in the Pleistocene layer
The Pleistocene layer is sinks slowly and naturally over the long term

9. SETTLEMENT OF THE GROUND SURFACE
The settlement of the man-made island can be almost attributed to the settlement of the settlement of the Pleistocene layer
The settlement across the island varies depend on the thickness of the clay layer and the weight of the reclamation material
The degree of the settlement decrease year by year and tending steadily towards an end

10. METHODS EMPLOYED AGAINST UNEQUAL SETTLEMENT
Balance established by soil removal
Compaction of the reclaimed layers
Raft foundation
Jack-up system

11. JACK-UP SYSTEM Main building is lighter then the adjacent structures
The difference in the depth of the settlement generate slight tilts between the main building and the adjacent structures
The pillars are jacked up under the main building in order to level the floor of the terminal