Fukuoka Sinkhole This massive sinkhole opened up in the middle of a road in Fukuoka, Japan on Tuesda
Fukuoka SinkholeThis massive sinkhole opened up in the middle of a road in Fukuoka, Japan on Tuesday. This hole formed as workers were digging a tunnel to extend a nearby subway.Sinkholes like this are common in areas where limestone rocks outcrop – natural acidity in groundwater can eat away at limestones, causing hidden caves to form at depth and grow until the weight above causes them to collapse. However, those sinkholes take centuries to form – they wouldn’t be associated with construction.The workers reportedly saw water appearing in the tunnel they were digging, tried to reinforce the walls, and then had to shift their priorities to protecting the nearby buildings as the sinkhole widened. In this case, water flowing in likely disrupted the sediment supporting the tunnel, causing the walls to cave in as it flowed. Stabilizing the hole now will involve either cutting off the water flowing to the site or stabilizing the walls themselves to prevent additional collapse inward.-JBBImage credit: Press report/fair use/BBChttp://bit.ly/2fetWrwhttp://bit.ly/2fRlvEv -- source link
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