Tuesday, October 31, 2017

What Lies Beneath? Questions Raised About Infrastructure Below

Quoted in Gina Mangieri's "Always Investigating" extensive coverage of the problems with underground cavities and sinkholes in Kakaako, What lies beneath? As Kakaako develops up, questions raised about infrastructure below.

This broken culvert was discovered in spring 2017 and required emergency repairs.


...

Driving through Kakaako lately has meant navigating a maze of emergency road work after underground near-collapses and even sink holes have popped up in the area.

“We have so many streets,” explained Panos Prevedouros, a University of Hawaii civil and environmental engineering professor, “so many likelihoods of a potential sinkhole.”

That’s because Kakaako was once a low-lying marsh, perfect for fishponds, salt, rice, and taro, but trickier for roadways and urban development we see now.

UH experts Always Investigating spoke with say the buckling roads are giving us signs of three things to watch out for:

Age of infrastructure like underground drainage culverts;
Rising sea levels and groundwater; and
Soil problems common to coastal areas.
“We have clay and sand, things that are easy to dissolve,” said Prevedouros, “and then because we have intrusion of sea water, or perhaps pipes, storm drains, and even sewers breaking, all that has the effect of diluting the soil and creating all kinds of cavities which pose a major threat to public safety.”

...

Experts agree the new structures are built to last and take all coastal-zone geographical challenges into account.

“The newer the buildings, the safer they are,” Prevedouros said. “The older buildings, they may start having problems with their foundations and they may have some tilting. Eventually they will have to have significant repairs and eventually demolition and reconstruction.”

...

“One of the side benefits of the rail project is they can help us with the geo-technical investigations they have done,” Prevedouros said, “and actually they can inform the neighborhood as to the stability of the soils, because they have to do it for their own foundations. Unless you plan to put a big rail or a big road in the area, you cannot simply start poking holes. It’s simply too expensive.”

...


No comments: