On September 6, the excavation of the Matsukawa section (4.9 km) of the Central Alps Tunnel for the Linear-Maximum Speed Rail in Iida City began. The excavation of the slanting tunnel (construction tunnel) began in Myokoto Park in Dingiriishi, Iida City, aiming to start digging the main tunnel in 2022. The excavated soil will not be left temporarily, but will be transported directly to sites in and outside the city for use. This is the first tunnel excavation in the city.
Initially, JR Tokai had planned to excavate the tunnel directly from the main shaft of the Chuou Alps Tunnel, but changed its mind and decided to dig the tunnel at the construction yard. "We knew it would be steep, but the ground surface was more fragile than we expected, so we want to proceed with construction while installing a slanting shaft and doing thorough slope work," he said.
The construction tunnel will be about 380 meters long and will be closed after the work is completed.
After the revision of the construction plan, the maximum number of vehicles to be used for construction is 270 per day (one way), which is the same as before the revision of the plan. The main purpose of the vehicles is to transport the remaining soil and materials, with the peak capacity of 60 vehicles for materials and 210 vehicles for remaining soil.
A temporary construction pier over the Matsu River connects the prefectural road Iida-Minamikiso line on the left bank with the city road Oyu-Myokoto line on the right bank, and the vehicles transporting the remaining soil travel one-way on both lines. The vehicles will mainly use the Chuo Road and the San-En-Nanshin Road to transport the overburden to the site.
For about a year, until next summer, it will be transported to a site in the Ashima district of Takagi Village, using the Iida-Minamikiso Line, the Haba-Osegi Line, and National Route 153 (Apple Road). A maximum of 80 vehicles per day (one way) will be transported.
About 1.85 million cubic meters of soil is expected to come out of the three pits in the city, 900,000 cubic meters from the Matsukawa construction area, 500,000 cubic meters from the Kuroda construction area, and 450,000 cubic meters from the Kamigo construction area.
The main shaft is planned to be 13 meters wide and 8 meters high, with an excavation cross-sectional area of about 100 square meters. The maximum soil cover is about 600 meters at a point about 3.2 kilometers west of the mine mouth. Due to delays in the preparatory work, the construction period is expected to be extended by one year and four months, and the construction period of the Matsukawa section of the Chuou Alps Tunnel will end in September 2026.
Info based on Summary of Japanese Media report: [ Monday, September 6, 2021 3:56 pm ] https://minamishinshu.jp/news/linear/%E ... 8C%BA.html
