9万5000立方メートルの岩に挑む！碓氷軽井沢IC近くの“高速道路の要塞”解体プロジェクトに親子が密着(abnステーション　2025.08.05）

Children observed the removal of a huge rock. A tour was held near the Usui-Karuizawa Interchange on the Joshinetsu Expressway to observe the work of removing a towering boulder. Children on summer vacation participated. A strange sight suddenly appears while driving along the expressway. Some on social media described it as "like a fortress." In fact, it's a construction site where a 70-meter-tall boulder is being removed. The site is approximately 2 kilometers from the Usui-Karuizawa Interchange on the Joshinetsu Expressway toward Tokyo. It's near the entrance to the Kitanomaki Tunnel in Annaka City, Gunma Prefecture. Removal work has been underway since 2017 due to the risk of rockfall. ■Mutsunori Yamagishi, Director, NEXCO East Japan Nagano Construction Office "There was 95,000 cubic meters of rock, but about 90% of it has been excavated." A total of 54 elementary school students and their parents participated in the event during their summer vacation. We headed to the construction site in a large elevator carrying heavy machinery up the mountain slope. ■Staff "It can carry up to 80 tons of heavy machinery." Since construction is being carried out while maintaining traffic on the highway, dynamite is not used and the rocks are carefully broken up and removed using heavy machinery. ■NEXCO East Japan Nagano Construction Office Director Mutsunori Yamagishi "So far, not a single small rock has fallen during excavation, so the work is proceeding safely." The rock mass, which was originally about 70 meters high, has now grown to 30 meters. But even so... ■From Gunma "Scary" ■From Gunma "It was so high and scary" Participants climbed onto the rockfall prevention roof and climbed on a large crane to observe the removal work site. ■ From Gunma "I'm glad we were able to participate and create some memorable memories for my family." ■ From Tokyo "There are so many buttons, like Zoom, and it seems like it would be difficult to operate a large crane." This is a major project to remove a 70-meter-tall boulder without blocking traffic. Construction is scheduled for completion in April 2029.