Machine control helps with earthquake reconstruction

In Japan the latest machine control technologies are being used to help with earthquake reconstruction.

Three years after the major earthquake that devastated Miyagi Prefecture on Japan’s main island of Honshu, the clean-up and reconstruction work is far from complete. In addition to rebuilding infrastructure and buildings, the Japanese Government has had to build a series of major improvements to flood protection.
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To help speed the rebuilding, sophisticated machine control systems were fitted to the earthmoving machines. Contractor Shimizu installed 1228 MOBA’s Xsite PRO 3D excavation system to move and landscape a total of 52,000m3 of earth within the necessary but tight time slot of just five months. A completely new dyke, taller than before, was built over a total length of 500m in order to ensure stronger and more effective protection against flooding. The tsunami that followed the massive earthquake had swamped the area, causing enormous damage. However the dyke had to feature a steep embankment with an incline angle of 50%, which was challenging to the construction team. But using the 3D system made the process easier than with conventional technologies.

First, the 3D model of the planned dyke, which had been previously created in the office, was transferred to the Xsite PRO system. This model provided the task specification for the excavator operator, along with the respective incline angle and depth specifications. Each work step had to be precisely recorded and represented on the display. Using sensors mounted on the boom, arm, bucket and chassis, the system was able to register the position of the bucket at all times. The machine position and orientation were determined by means of GNSS. The display showed the values in the terrain model, so the excavator operators could recognise when the desired incline angle and depth had been attained and where further material needed to be moved. This allowed the dyke to be built precisely according to the model.

According to the contractor, this resulted in time savings of 15%. Meanwhile there was no need to place stakes on the site, further reducing the time and expense of the job, while it was also possible to avoid having to hire two surveyors for the task of surveying.