(Construction) - Kajima Corporation announced on May 25 that it has completed the excavation of a water pipeline tunnel using a hybrid tunnel boring machine that can also work in the NATM.
The machine was jointly developed with construction machinery maker Komatsu. This is the first time in the world that a single tunnel boring machine can be used in both methods. The machine named as "NATBM" was introduced at the site in Itoigawa City, Niigata Prefecture by the contractors Kajima and Sato Kogyo. The total length of the tunnel is 3.8 km. The construction started in July 2017 and is scheduled to complete in October 2022.
|Japan's Kajima completed TBM/NATM hybrid tunnel.|
The tunnel was excavated in TBM mode up to the border of the serpentine layer, and switched to NATM mode for the mixed serpentine section where the geology became complicated. In the NATM mode, the bucket excavator, which was built into the cutter head, was used for excavation, and earth was taken in through the opening and carried out to the back, and then the tip was replaced after excavation for concrete spraying and rock bolting. Kajima has confirmed the effectiveness of the machine and is aiming to expand the application of the system to TBM construction.(2021/05/26)
The Daily Engineering and Construction News of Japan