Japanese contractor Obayashi has found a novel way to tackle labor shortage and an aging workforce with its dam-building robots.
The robots have been trained to stack concrete layers one on top of the other to form the dam. A plant has also been built near the site to mix sand and gravel with cement to make concrete.
Transferring expert techniques to machines could enable the company to analyze what was once ‘implicit knowledge’, intones Akira Naito, head of Obayashi’s dam technology unit.
According to the Nikkei Asian Review, every process of constructing the 84-meter-high, 334-meter-wide dam in Mie Prefecture will involve some form of automation.
This includes the initial work of establishing the foundation, and pouring concrete to form the body.
The dam’s body is built in layers by pouring concrete into 15-meter square partitions. Tower cranes that pour the concrete are controlled remotely by office computers, which also monitor the positioning of the partitions and the progress of construction.
Building a dam is an intricate endeavor that requires all crevices to be sealed to prevent breaches.
Concrete surfaces need to be processed so they are tightly stacked on one another. Layers that are uneven are usually brushed down by human professionals until they are flat.
Obayashi’s machines have been trained to handle this brushing: The frequency of the cyclical brushing and the pressure on the surface are automatically controlled.
As poured concrete builds up, the forms used to give it structure need to be raised to keep unset concrete from leaking out.
Normally, skilled workers in heavy machinery operate in tandem to gradually lift the forms.
Obayashi has done away with this too by building a robot that can handle this task as well.
The end-goal according to Naito is to cut building time by 30%. At present, Obayashi’s automation has only increased productivity by about 10% as it still requires people to man the site if things go south.
Other Japanese contractors like Kajima too have built self-driving bulldozers and dump trucks so construction can continue 24 hours a day.
It has automated the lifting of concrete forms, which it used at a dam construction site in Hokkaido for the first time.
Image and content: Obayashi/Nikkei Asian Review