About geophysical exploration other than around the depression of the outer ring road in Tokyo

Thank you for your continued understanding and cooperation in the Tokyo Outer Ring Road Project.

In the vicinity of the tunnel construction site at 2-chome, Higashi Tsutsujigaoka, Chofu City, depressions in the ground surface and cavities in the ground have been confirmed, and we are causing inconvenience to everyone in the area, such as closing roads.

Currently, we are investigating the cause and effect of the collapse event and tunnel construction, but the "4th Tokyo Outer Ring Tunnel Construction Review Committee Expert Committee" held on November 27, 2020 We would like to inform you that the geophysical exploration (microtremor array exploration, surface wave exploration) to be additionally investigated will be carried out from the end of December for the Setagaya Ward and Komae City sections.

Please see the Tokyo Gaikan Project website for the geophysical exploration schedule.