Sequential road collapse “Causes of excessive sediment” Caused by Yokohama August 3 at 7:53
Regarding the consecutive collapse of roads in Yokohama in June, the "Railway and Transportation Organization" said that when excavating a tunnel underground, the excavating machinery took in too much sand and created a gap in the ground. It was clarified that it was possible that it was done.
In June this year, two places about 300 meters apart collapsed one after another on a road called "ring 2" in Kohoku Ward, Yokohama City.
At both sites, underground tunnels are under construction, and the "Railway and Transportation Organization" that undertakes the construction has set up a committee of experts to investigate the relationship with depression.
As a result, it was presumed that it was presumed that a machine called a “Shield Machine” that digs underground under the influence of geology, etc. excessively took in the earth and sand and created a gap underground.
Furthermore, we did not continuously monitor the amount of earth and sand excavated in real time, we could not confirm excessive intake of earth and sand, and we could not fill the gap.
The “Railway and Transportation Organization” will examine the ground again in detail, and will proceed with the construction by taking recurrence prevention measures such as appropriate management of underground conditions and strengthening of the monitoring system.