ABSTRACT
There are increasing demands to construct tunnels without skilled laborers as facing a decrease in the number of laborers in the tunnel industry in Japan. The construction automation of tunnel linings with Self-Compacting Concrete (SCC) has been developed to be constructed without skilled laborers. Concerning placing the SCC, managing the placement and predicting the flow of the SCC is critical for verifying the construction automation.
The full-scale experiment was carried out with the construction automation. The full-scale lining formwork was prepared to construct the lining that is 9.22 m wide, 6.61 m high, 10.50 m long, and 0.40 m thick. The SCC was alternately placed through the steel pipe installed on the lower center of the right and left side of the formwork using a concrete pump until the formwork was filled with it. The placement of the SCC and the pressure acting on the formwork were monitored in real-time. During the experiment, the volume of approximately 80 m3 of the SCC was placed.
The lining concrete was placed in approximately 3 hours with 3 skilled laborers. Also, the post-investigation showed that the lining concrete could be placed with quality using the concrete pump only. The proposed construction automation of the tunnel lining can contribute to reducing the number of skilled laborers, and improving quality and safety.
