Civil engineering Seminar on G Cans Underground Flood Control Tunnel Japan .

1. Prof Ram Meghe Institute ofTechnology &
Research, Badnera-Amravati.
• G CANS PROJECT , TOKYO FLOOD TUNNEL
(SEWER SYSTEM) , JAPAN.
• Presented by :- Mayur .U. Rahangdale
Department of Civil Engineering
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2. CONTENTS
1. Introduction
2. Flood
3. Need for the underground water diversion facility
4. Working of G Cans sewer system.
a) Duct (intake facility)
b) Silos
c) Tunnels
d) Underground storage tank
e) Turbines
5. The furukawa reservoir
6. Conclusion
7. References
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3. 1. INTRODUCTION
• The official name of the long, underground tunnels is the “Metropolitan Area Outer Underground Discharge
Channel”, but is more commonly called G-Cans.
• It is the world's largest underground flood water diversion facility.
• It is located between Showa in Tokyo and Kasukabe in Saitama prefecture, on the outskirts of the city of Tokyo,
Japan behind a small government building, underneath a soccer field and skateboard park.
• Work on the project started in 1992 and was completed by early 2006 at the cost of $3 billion
• It consists of five concrete silos with heights of 65 m and diameters of 32 m, connected by 6.3 km of tunnels, 50
m beneath the surface, as well as a large water tank with a height of 25 m, length of 180m, a width of 80m, and
with 59 massive pillars connected to (13,000 hp) pumps that can pump up to 200 tons of water (the approximate
equivalent of a standard 25 meter pool) into the Edo River per second.[4]
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4. 2. FLOOD :-
A flood is an overflow of water that submerges land that is usually dry.
Fig 2.1 - Kerala flood august 2018 :-324 deaths fig 2.2 - Tokyo flood 1990 :- destruction of 30,000 homes
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5. 3. NEED FOR THE UNDERGROUND WATER DIVERSION
FACILITY
The Tone, Are and Edo Rivers had been terrorizing the people of greater Tokyo for generations with their periodic
monsoon-season flooding and Typhoons. In September 1991, the worst storm to strike Japan in 30 years. 30 000
homes and 100 square kilometres (25 000 acres) of land in the Tokyo were flooded, causing a total of 52 deaths in
Japan
To protect the city’s 13 million residents from heavy rainfall and tropical storm floods,
The simplest solution would have been to build a reservoir. But the question facing urban planners was :-
How to build a reservoir In a city twice as dense as New York ? The answer : Build it underground. The result
were Metropolitan Area Outer Underground Discharge Channel.
"The project aims to protect the city of Tokyo itself from floods during heavy rainfall and typhoons."
The Metropolitan Area Outer Underground Discharge Channel gathers the overflowing flood waters from
rivers in Tokyo, such as Oochi Kotone, Kuramatsu, Nagakawa and Arakawa, and drains it into the Edogawa
River.
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6. 4. How It Works :-
• Fig 4.1 – working.
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7. Fig 4.2 - Map
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8. Fig 4.3
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9. Fig 4.4
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A) DUCT

10. 10

11. WATER IS CHANNELED UNDERGROUND
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12. 65 m in height and 32m diameter.
B) SILOS :-
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13. The top of the shaft (silo) 13

14. C) TUNNEL :-
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15. 6.3 KM LONG , 50 M UNDERNEATH THE RIVER BASIN ,10 METRES IN DIAMETER.
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16. 180m long, 80m wide and 25 m high, The roof is supported by 59 massive pillars.
D) UNDERGROUND PARTHENON {STORAGE TANK}, [THE TEMPLE]
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17. Large water storage tank is connected to four (13,000 hp) modified jet engine turbine pumps that can pump up to
200 tons of water (the approximate equivalent of a standard 25 meter pool) into the Edo River per second.[4]
E)TURBINES :-
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18. The Edo River into which up to 200 tonnes of water per second is pumped though huge channels.
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19. Entrance 19

20. THE FURUKAWA RESERVOIR
• 3.3-km-long subterranean reservoir will be able to hold 135,000 cu. meters of water, enough to fill 54
Olympic-size swimming pools.
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21. CONCLUSION
• Flood tunnels are an important part of flood and storm water management system. They are used
where space is limited – often in urbanised areas such as Tokyo, or in Kualur Lumpur.
• The Metropolitan Area Outer Underground Discharge system was built to handle flooding from monsoon-
season typhoons and has been used over 200 times.
• Government figure said , the project likely saved around 430 million dollars in property damage alone since it
become fully operational. 21

22. REFERENCES :-
• "LAIR OF THE BALROG". Accessed 10 January 2015
• Jump up^ "CNN How giant tunnels protect Tokyo from flood threat".
• Jump up^ "G-Cans: Tokyo's Massive Underground Storm Drain".
• Jump up^ "G-Cans Project, Kasukabe, Saitama, Greater Tokyo Area, Japan". Retrieved 10
January 2015
• Jump up^ http://www.ktr.mlit.go.jp/edogawa/gaikaku/english/index.html
• Jump up^ "Catalyst: Tokyo Flood Prevention - ABC TV Science". ABC - Australian
Broadcasting Corporation (Video Documentary). 2014-10-23. Retrieved 2015-03-20.
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23. Thank You...!
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