Japan subway construction causes sinkhole

Sinkholes. They swallow houses, they devour cars. They eat up road, and they’re happening around the world. A section of a five-lane street in Japanese business district Fukuoka was swallowed on Wednesday in what is being called a sinkhole. Subways were delayed and 800 houses were left without power. The sinkhole happened uncomfortably close to other buildings, so officials evacuated the people in the surrounding area to minimize the chance of any injury due to exploding gas lines or any further sinkholes. There were no injuries reported.

The Mayor of Fukuoka said that the sinkhole occurred due to construction on a subway line extension nearby the collapsed road. Exposed, severed sewage pipes leaked water into the sinkhole  due to the collapsing of the street.

The United States has also had its fair share of sinkholes. The worry with sinkholes happening on roads, especially in America, is that gas transmission lines and subways could be affected by collapsing sections of road – very much like Japan. Donald Trump has promised that under his presidency, roads would be repaired.

Construction works play a part in making surrounding areas’ ground unstable. A 2005 book named Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction details how sinkholes induced by ground disturbance occur.

Vibrations from construction traffic could conceivably induce sinkholes in unstable soil cover, but their effects appear to be masked by the greater influence imposed by drainage modifications.

Vibration caused by cars driving over unstable roads are also a contributing mechanism that can cause the roads to collapse. This happens if the road is already weakened by something like other construction work or more pressing issues like burst pipelines.

Water erosion is usually also factored in when explaining why a sinkhole happened, however, vibration seems to be what the municipal government of Fukuoka is going with.

Construction crews are working around the clock to have the street repaired by next week. Workers will also presumably get back to work once the street is repaired. Fukuoka’s Municipal Government is patching the road up with cement. Government officials say that 7,000 cubic meters of soil are required to repair the street.

The certain kind of sinkhole observed in Japan is called a cover-collapse subsidence hole. It suddenly appears and continues to collapse. Engineers that are experienced in sinkhole remediation are now tending to the sinkhole in Japan. The support beams of buildings were exposed during the collapse, and as a result, engineers now need to ensure the foundations of buildings are still reinforced and not affected by the sinkhole.