Another sinkhole found on Lower Wheaton Way

BREMERTON — In the early morning hours of May 18, a photo was posted to the Manette Neighborhood Coalition Facebook page showing a man standing in a waist-high sinkhole near the Lower Wheaton Way roundabout. It was the second sinkhole in less than a week found along the city’s newly paved road.

BREMERTON — In the early morning hours of May 18, a photo was posted to the Manette Neighborhood Coalition Facebook page showing a man standing in a waist-high sinkhole near the Lower Wheaton Way roundabout.

It was the second sinkhole in less than a week found along the city’s newly paved road.

Tom Knuckey, city engineer, said a depression was found in the same place as the sinkhole about a week ago.

It turned into a sinkhole late Sunday evening and was repaired Monday morning.

The sinkholes don’t appear to be for lack of caution prior to construction. The city used small in-pipe cameras to inspect all the underground piping in the construction zone during the project design, and again after the voids were discovered, according to Knuckey.

Repairs were made as problems were found, Knuckey said.

One such instance was to a lateral sewer pipe found near the roundabout. Knuckey said it was fixed during the construction using cured in-place piping, a method that doesn’t require excavation.

Following the construction, Knuckey said there was never an indication that the area might pose a problem.

“In the area down by the roundabout, it is an area that was standing up fine,” Knuckey said. “We had no indications that there was a problem.”

The contractors left the existing pavement in place and only removed it when needed.

“There was voids below grade that we had no idea even existed,” Knuckey said.

Knuckey believes the heavy vibratory roller compactors that follow pavers likely jarred some earth loose, which then fell into existing voids.

“When you put those very heavy roller compactors on the asphalt you put a lot of the energy into the ground,” Knuckey said.

At this point, there’s nothing the city can do to prevent future sinkholes, Knuckey said.

Only time will tell if the sinkholes are an anomaly or a sign of things to come.

“I would hope that that’s the last one,” Knuckey said. “We’ll have to wait and see.”

 

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