is a Japanese concept for the public use of deep underground, enabled by a 2001 law. It was first thought of in the late 1980s as Japan faced ever-increasing land values in the

economic bubble An economic bubble (also called a speculative bubble or a financial bubble) is a period when current asset prices greatly exceed their intrinsic valuation, being the valuation that the underlying long-term fundamentals justify. Bubbles can be c ...

, to allow the use of heretofore-unused deep underground for necessary water and utility ducts and other city

tunnel A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...

s. However, due to technical difficulties in ventilation, emergency procedures and other safety-related issues and the relatively high cost, no projects using deep underground have been completed as of 2010.

Definition

* Depth greater than 40 meters or * Depth 10 meters greater than the layer on which

deep foundation A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element ...

rests In the case of public use, no compensation to the land owner is required.

Projects using the law

* Underground water mains in

Kobe Kobe ( , ; officially , ) is the capital city of Hyōgo Prefecture Japan. With a population around 1.5 million, Kobe is Japan's seventh-largest city and the third-largest port city after Tokyo and Yokohama. It is located in Kansai region, whic ...

(

Chūō-ku, Kobe is one of 9 wards of Kobe, Japan. It has an area of 28.46 km², and a population of 127,602 with 74,814 households as of January 31, 2012. The ward was formed from the 1980 merger of the former Fukiai-ku () and Ikuta-ku (). The Consulat ...

) ** Project approved on June 19, 2007 (first ever in Japan). *

Tokyo Gaikan Expressway The is a national expressway in Japan. It is owned and operated by East Nippon Expressway Company. Overview The name Gaikan refers to the route's status as an outer ring road (beltway) for Tokyo. The expressway is also referred to simply as Ga ...

(Tōmei Junction - Ōizumi Junction/Interchange) ** Project status elevated to construction stage on April 27, 2009.

Projects anticipated to use the law

* Capacity expansion of

Chūō Main Line The , commonly called the Chūō Line, is one of the major trunk railway lines in Japan. It connects Tokyo and Nagoya, although it is the slowest direct railway connection between the two cities; the coastal Tōkaidō Main Line is slightly faste ...

(extension of

Keiyō Line The is a railway line connecting Tokyo and Chiba in Japan, paralleling the edge of Tokyo Bay. It is operated by the East Japan Railway Company (JR East). The line forms part of what JR East refers to as the around Tokyo, consisting of the Kei ...

from

Tokyo Station Tokyo Station ( ja, 東京駅, ) is a railway station in Chiyoda, Tokyo, Japan. The original station is located in Chiyoda's Marunouchi business district near the Tokyo Imperial Palace, Imperial Palace grounds. The newer Eastern extension is ...

Mitaka Station is a passenger railway station located in the city of Mitaka, Tokyo, Japan, operated by the East Japan Railway Company (JR East). Lines Mitaka Station is served by the Chūō Main Line, acting as the terminus for all-stations Chūō-Sōbu Line ...

) * Extension of

Tsukuba Express The , or TX, is a Japanese railway line operated by the third-sector company Metropolitan Intercity Railway Company, which links Akihabara Station in Chiyoda, Tokyo and Tsukuba Station in Tsukuba, Ibaraki. The route was inaugurated on 24 Augu ...

from

Akihabara Station is a railway station in Tokyo's Chiyoda ward. It is at the center of the Akihabara shopping district specializing in electronic goods. Lines Akihabara Station is served by the following lines. JR East: * Tōhoku Main Line ** Keihin-Tohoku Li ...

to Tokyo Station *

Chūō Shinkansen The is a Japanese maglev line under construction between Tokyo and Nagoya, with plans for extension to Osaka. Its initial section is between Shinagawa Station in Tokyo and Nagoya Station in Nagoya, with stations in Sagamihara, Kōfu, Iida an ...

(a total of 100 km of deep underground track in Tokyo, Nagoya and Osaka areas) *

Hanshin Expressway The is a network of expressways surrounding Osaka, Kobe and Kyoto, Japan. Operated by , it opened in 1962. Portions of the Hanshin Expressway about east of Fukae Station collapsed during the Kobe earthquake on 17 January 1995. These section ...

Route 2 Yodogawa-Sagan Line third phase (extension from Toyosaki,

Kita-ku, Osaka is one of 24 wards of Osaka in Japan. Incidents and accidents 2021 Osaka building fire Notable locations Kita-ku, particularly the Umeda area surrounding Osaka Station, is one of the main commercial centers of Osaka. Kita-ku is also a fina ...

to Hiejima, Kadoma)

External links

Law on Special Measures for the Public Use of Deep Underground
(大深度地下の公共的使用に関する特別措置法 dai-shindo chika no kōkyō-teki shiyō ni kansuru tokubetsu sochihō or 大深度地下使用法 dai-shindo chika shiyōhō)

* ttp://search.japantimes.co.jp/cgi-bin/nb20080331a1.html Group plans to bury Tokyo's elevated 'shuto' Civil engineering {{Architecture-stub