[JP] Tokyo: linear maglev tunnel construction

[Miss Maglev]

Investigation excavation of Higashi Yurigaoka emergency exit 'completed without problems' JR Tokai's linear tunnel construction

　JR Tokai announced on October 2 that the construction of the first Metropolitan Area Tunnel of the Linear Central Shinkansen, to be dug more than 40 metres underground, was completed on September 29, after the excavation of the Higashi Yurigaoka Emergency Exit (Asao Ward, Kawasaki City) began in March. JR Tokai will compile the results of the survey and hold a briefing for local residents.
　JR had previously announced that the excavation from the emergency exit towards Nagoya would be 150 metres, but the actual excavation distance was 133 metres. JR claims that there are no problems because the excavation was completed at the distance necessary to install equipment behind the shield machine.
　Of the total length of the First Metropolitan Tunnel, which is about 37 kilometres, 33 kilometres are deep underground. The tunnel was excavated 124 metres from the Kitashinagawa emergency exit in Shinagawa Ward, Tokyo, 75 metres from the Kajigaya emergency exit in Miyamae Ward, Kawasaki City, and 17 metres from the Onoji emergency exit in Machida City, Tokyo.
The Kitashinagawa Emergency Exit, which will be reopened in May, was excavated 124 metres for the linear survey.

Source: Translated info from https://www.tokyo-np.co.jp/article/281229 Accessed: 2 October 2023

[Miss Maglev]

Linear Tunnel "Survey Digging" Suspended Again; Excavator Dents in Shinagawa, Shifting Inner Wall; JR Tokai: "No Safety Issues"　

.

2023-10-06_Linar Tokyo 2

. Location
Source: https://www.tokyo-np.co.jp/article/282146 Accesssed October 6, 2023

　JR Tokai announced on October 6 that it has found damage to a shield machine (excavator) and will temporarily suspend excavation of a 300-meter section of the Linear Central Shinkansen tunnel from the North Shinagawa emergency exit (Shinagawa Ward, Tokyo) to the Nagoya direction. This section was scheduled to be excavated by March 2022 as an "exploratory excavation," but the excavation has been suspended twice, including this time. Only 124 meters have been dug, and the completion of the excavation is expected to be delayed until the end of 2012.

　According to JR Tokai, a part of the excavated soil gradually adhered and hardened at one spot on the outside of the excavator, and the pressure caused a 7 cm-deep dent toward the inside of the tunnel. This made it difficult to assemble the reinforced concrete segments (wall blocks) that would form the tunnel's inner walls, and some of the segments were assembled up to 3 cm inward. The company claims that it has no safety problems because it allows an error of up to 5 centimeters in assembly.

　This section of the Linear Central Shinkansen Line has the steepest curve between Shinagawa and Nagoya (curve radius 900m). The company believes that the cutter's method for digging out the curve can be improved to prevent soil from sticking to the curve, and after repairing the dents, excavation will resume next spring. The excavated section will be part of the First Metropolitan Tunnel, where linear trains will run in the future.
　The excavation began in October 2009 to investigate the effects of the construction of the Tokyo Outer Ring Road (Outer Ring Road) Tunnel, which, like the Outer Ring Road, is excavated at a depth of 40 meters or less below ground level, after sinkholes and cavities were found in the construction of the tunnel in Chofu City, Tokyo. Construction was suspended in March 2010 due to damage to the excavator, and resumed in May of this year. (Mitsuharu Umeno)

Source: https://www.tokyo-np.co.jp/article/282146 Accesssed October 6, 2023

2023-10-06_Linar Tokyo 1

Kitashinagawa emergency exit of the Linear Central Shinkansen (right) and stacked segments (wall blocks, bottom)
Source: https://www.tokyo-np.co.jp/article/282146 Accesssed October 6, 2023

[Miss Maglev]

JR Tokai announced on April 6 that the construction of a tunnel near Shinagawa Station in Tokyo, the starting point of the Linear Central Shinkansen Line, has been suspended again due to a problem with a shield machine, a large excavation machine. A part of the steel casing that houses the machine's equipment has been found to be deformed, and the work is expected to resume next spring. The shield machine is scheduled to be used in the Kazakoshi Tunnel in Iida City.

　Construction has been suspended at the Kitashinagawa section of the First Metropolitan Tunnel, where excavation of the "deep underground" began in October 2021 as part of an investigation excavation.

Source: Translated info from Japanese: https://www.shinmai.co.jp/news/article/ ... 3100700131 Accessed: 2023-10-07

.

2023-10-07_Boring_Machine

CNTS2023100700132_M[1].jpg (461.27 KiB) Viewed 506 times

.
Source: https://www.shinmai.co.jp/news/article/ ... 3100700131 Accessed: 2023-10-07