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A special method to build and anchor bridge pillars is used in Japan.
||From 2014 and still going (end January 2015)
||Building a new bridge
||PVE 55M & PVE 600 power pack
Next to the bridge of Highway 302 (Nagoya Loop Road No.2) in the Ama District, our customer, Marutai Doboku CO. LTD., is building a second one. Due to the poor soil conditions a special method is used to build and anchor the bridge pillars.
Thirty casings with a diameter of 1000mm and a thickness of 14mm were placed in a circle with a total diameter of just about 12 meters. Marutai welds a special profile on two sides of the casings (see illustration). These tube shaped profiles grabbing together perfectly when they are placed. After they were filled, there arose a watertight separation. Water and soil can be removed until the desired depth is reached and the construction of the foundation of the bridge pillar can be initiated. The casings remain an important part of the foundation. After the bridge pillar is finished the casings are cut just above the foundation level.
The soft seabed on site and the required capacity of the foundation has ensured that the tubes had to be no less than 30 meters long. Three pipes were welded on top of each other on site after the previous casing was vibrated with the PVE 55M
into the soil. When the hard layer was reached a IHC Hydrohammer was used to pile the casing a bit further.
Because this is a complex job, it was decided not to carry out the work from a barge but from a special built metal pier. On the Google Earth picture above it is clearly visible. An advantage is that vehicles and cranes can reach near the workplace that there can be worked on several pillars simultaneously. Marutai Doboku has more than 50 years experience in the foundation construction field. According to Mr. Shimizu of ITC Corporation, one of our Japanese PVE dealers, Marutai Doboku expects that this foundation method will be expanded to other Asian countries.