Last week, Japanese construction workers earned plenty of praise after they were able to repair a gigantic 90 foot by 88 foot by 50 foot sinkhole that formed in Fukuoka, Japan in the middle of a 5 lane road in under a week. A timelapse video of the repair can be watched by clicking here. This week, CNN reported that the road had to be closed again after it began to sink again.
According to the reports, sections of the repaired road sunk up to 2.7 inches (7cm) in some areas causing some public concern. The road has since been reopened, but the road sinking like this should not be a huge surprise, especially to those on the earthwork side of things. After having to fill the hole with roughly 200,000 cubic feet of soil in such a short period of time, it was not possible for the soil to reach peak compaction. Each cubic foot of soil can weigh between 74 and 110 pounds, so, using a conservative estimate of 92 pounds per cubic foot, that’s equals almost 20 million pounds of material. That extreme amount of weight is bound to cause some considerable settling.
The mayor of Fukuoka, Takashima Soichiro, took to Facebook to apologize to the residents for not warning them the road may sink again. It has since been reopened, but the settlement could continue for a while longer. The city recently sustained an earthquake, which measured a 3 on the Richter scale, which may have also contributed to the drop.
You can watch the video of the repair, by Hakata,JAPAN LOVE, again below:
