Swampy soil, design error cause 120th Ave. delays

Shifting, swampy soils have caused a major delay in a construction project meant to tie together two growing neighborhoods of Bellevue.

The 120th Avenue Northeast corridor project was slated to finish midway through 2016, but finds work ongoing until at least July, according to the project’s design manager. Several retaining walls along the project had shifted forward several inches, necessitating a pause and rebuild.

David Grant, Bellevue’s Transportation public information officer, said the 120th Avenue corridor was a vital project for the city’s growth.

“It’s a connector between Downtown and the Bel-Red area, two areas slated for growth,” he said. “Light rail will be right there, and the Spring District is very near.”

Unfortunately, that memo didn’t make its way to the peaty, sandy soil near Lake Bellevue. Several retaining walls used to hold back soil during construction had moved several inches, prompting a reevaluation of the walls and a significant delay.

The section of road in question is 120th Avenue Northeast between Northeast 8th Street and Northeast 12th Street, near Lake Bellevue. The project is designed to widen 120th Avenue Northeast

“Obviously we try to complete projects in a cost-effective manner,” Grant said. “But safety is our number-one priority.”

Three of the six “soldier pile” walls, ranging from 100 to 200-feet long and four to eight feet high, were bulging and shifting, causing potentially unsafe conditions. The contractor in charge of the project, Goodfellow Bros., Inc. was authorized to increase its budget by $5,323,122 to cover the delays. The new total for the project is $45,394,554.

The solution is to build stronger, sturdier walls, Grant said.

Paul Krawczyk, the project design manager, said that the designs used in the project were new to city projects, which might account for the design flaw causing the walls to shift.

Grant said the delay was unfortunate but hard to foresee.

“Any delay is longer than we would like,” he said. “But we are especially sensitive to those businesses along 120th.”

He said an apparent design error in the engineering planning for the project could see the City of Bellevue recouping some of that $5.32 million cost over budget.