The SkyTrain Lobby and many Vancouver politicians are claiming that a Broadway subway tunnel will be bored in stead of cut-and-cover, eliminating the many problems caused to those living or have businesses adjacent to the subway route, thus eliminating protracted litigation for compensation. The problem of course is a bored tunneling causes it own set of problems and may pose a serious threat to many older and some not so old, building’s foundations. Some of the problems expected to be encountered by businesses and residents along the proposed Broadway/UBC subway will be cracked floors and foundations, sinkholes large enough to swallowed driveways, pollution, homes flooded with sewage, etc.
Despite the myth that a bored subway tunnel under Broadway will be problem free unlike a cut-and-cover subway, they are not and have a host of their own unique and expensive problems. Knowing how niggardly TransLink and the provincial government are paying compensation to those affected by subway construction on Cambie Street, a bored Broadway subway tunnel may leave thousands of property owners with very expensive repair bills and years of expensive litigation.
From the Seattle Times –
Bridgewater tunnel likely causing homes’ troubles
By Keith Ervin
Tom and Jan Glithero were pointing out the recently discovered cracks in their reinforced-concrete patio the other day when Tom called out, “Oh, guess what? Here’s another one! So there’s four cracks now — great.”
“The more we look, the more we find,” Jan added.
The Bothell couple first found long, wide cracks in their garage and driveway the middle of last year.
But it wasn’t until November, after they saw hairline cracks between the bricks of their living-room fireplace, that it occurred to them that a tunnel excavated beneath their backyard for the Brightwater sewer-plant pipeline might be causing the ground to settle.
Since then, engineers and insurance adjusters have made repeat visits to the Glitheros’ split-level house and installed instruments to determine whether the house is continuing to settle.
“We’re working with the assumption it is attributable to Brightwater construction,” said King County Wastewater Treatment Director Christie True.
The Glitheros are among dozens of residents of King and Snohomish counties who have been affected by the $1.8 billion sewer project that began in 2006 and won’t be completed until 2012, more than a year behind schedule.
The 13-mile tunnel will carry treated wastewater from the Brightwater plant north of Woodinville to Puget Sound off Point Wells in Shoreline. King County is responding to complaints even as Sound Transit prepares to dig twin light-rail tunnels between downtown Seattle and the University of Washington and the state Department of Transportation designs a large-diameter tunnel to replace the Alaskan Way Viaduct.
Neighbors of Brightwater have complained of construction noises late into the night, cracked floors and foundations, a sinkhole that swallowed a driveway, pollution of a creek, homes flooded with sewage and wells gone dry.
One worker died in a construction accident, and two of four tunnel-boring machines have been idled since last June while undergoing repairs more than 300 feet underground. The broken-down machines have slowed the project and will drive up costs by a yet-unknown amount.
The state Department of Labor and Industries fined tunnel contractor Vinci/Parsons RCI/Frontier-Kemper $6,600 for workplace-safety violations after worker David Keith was killed by a steel beam that fell from a crane at the North Kenmore tunnel portal in November 2006. Keith’s family is also suing contractors and the county.
Most of the complaints have been filed by people who live along the tunnel route. The tunnel runs under Northeast 195th Street and other roads, and directly beneath 147 private properties, officials said.
To date, King County and its insurance carrier have paid more than $400,000 in construction-related damage to homeowners, businesses and the county itself.
“I would say for a project of this size and the amount of liability insurance we carry, the loss is very small,” True said. The costliest project in county history has mostly gone well, officials say. Construction of the treatment plant itself is on schedule, the eastern end of the tunnel is complete, the west portion is almost done, and a mile-long outfall pipe was installed faster and cheaper than expected.
But for some neighbors of the project, it’s been anything from a nuisance to a nightmare. Several said they were initially impressed by the quick response of the county and its contractors to their complaints, but then grew frustrated by lengthy delays in resolving problems.
Here are some of the things neighbors have endured:
• The well that provides water to Jorge and Shirley Landa’s Bothell house and dog kennels stopped working when the pump burned out. A replacement pump also burned out before they realized sand was clogging the filter. Then the water level dropped and the well went dry.
The Landas also noticed that Horse Creek, which runs through their property, was behaving strangely. “You could sit in the car and you could hear the creek bubbling up like Old Faithful,” Shirley said.
The state Department of Ecology concluded that the creek was repeatedly muddied and its water chemistry changed over a three-month period by compressed air that worked its way from a tunnel-boring machine through 160 feet of soil to Horse Creek during scheduled maintenance.
The Landas’ well is back in operation but exhibiting new problems they’re trying to understand.
• Marlene and Eldon Berg’s previously quiet Kenmore neighborhood became a noisy construction site, with truck engines revving, backup beepers sounding and metal banging on metal when contractors began digging a tunnel portal. Windows in their home rattled and floors shook when a boring machine chewed its way out of the portal. After the Bergs’ well ran dry, the county hooked them up to the city water system.
• Ray Ames was asleep when his wife, Mary, woke him up and showed him a brownish liquid flooding the kitchen and pouring out of the toilet. Raw sewage had backed up into the house because of pump problems on a Kenmore sewer line that was being redirected to the Brightwater plant.
Two years later the county paid more than $70,000 for repairs and legal fees.
• Pauline Chihara stepped out of her Kenmore home early one morning and discovered her driveway had fallen into a 30-foot-wide, 15-foot-deep sinkhole. County contractors quickly filled the hole and did a temporary repaving job. The ground had caved in because a tunneling machine removed too much soil 150 feet beneath the house.
That was in March 2009. As for a permanent fix to the driveway and sidewalk, Chihara said, “They said they were waiting for warm weather. Warm weather came and passed. … I wish they would just hurry up and do it. I don’t know what they’re waiting for.”
County spokeswoman Annie Kolb-Nelson said Chihara shouldn’t have had to wait so long for repairs and said she would try to speed up the process.
“I appreciate people’s patience while we get this project done,” wastewater chief True said. “It’s essential that we get it done. We recognize that some people will be inconvenienced. Any time there is a concern or complaint we want to get out there and respond as quickly as we can.”
After the Glitheros began finding cracks around their house, the county sent out an engineer who found a crack in the foundation. More recently, as Tom relaxed in the living room, he looked up and exclaimed “Holy mackerel!” when he saw a new crack in the vaulted ceiling.
Now push pins mark five cracks in the ceiling so the Glitheros can tell if they are lengthening.
“There’s a connection here and it’s not healthy,” Tom said of the problems. His biggest worry is what the settling will mean when he and Jan try to sell the house they lived in for 30 years: “I wouldn’t buy the house.”