Work piles on to make new school earthquake proof

MARYSVILLE Workers are driving more than 250 concrete piles 60 feet into the soil at the Grove Elementary School construction site to make the new, two-story building safer in earthquakes.

  • Thursday, August 28, 2008 11:47am
  • News

A construction crew from McDowell Northwest uses a huge crane to bore one of 257 holes into the ground last week at the site of the Marysville School Districts new elementary school. Each one of the 60-foot-deep holes will be filled with a rebar cage and concrete to create hundred of stilts to support the slab floor in case of an earthquake.

MARYSVILLE Workers are driving more than 250 concrete piles 60 feet into the soil at the Grove Elementary School construction site to make the new, two-story building safer in earthquakes.
The 54,000-square-foot structure will house up to 550 students plus additional staff and visitors, and engineers stipulated the need for 257 pilings to support the concrete floors in case of a temblor.
A crew from McDowell Northwest Inc. is using a huge crane to make the auger cast pilings deep in the ground at the intersection of Grove Street and 67th Avenue NE.
You either need to excavate down to the good soil or drive piles down to it, explained Bruce McDowell, company vice president and general manager. Its a fairly large job.
Pilings have been used as supports for buildings since the middle ages, he added, and his company is working on a wastewater treatment plant in Mount Vernon that will require more than 600 pilings. In the auger cast piling technique a big drill head measuring 18-inches in diameter, with a hollow center, is pushed and twisted into the earth. As it delves deeper into the soil a cement-based grout is pumped at high pressure through the hollow tip. As the auger drills the soil the grout pushes the loose dirt up through the remaining hole, so engineers and geologists can inspect the spoils brought back up as the auger is slowly withdrawn from the hole.
The holes at the Grove site are 18 inches in diameter and go down 60 feet. After they are filled with concrete a 30-foot-long steel cage made of reinforcing bar is vibrated into the pile, with a central steel beam or bar going all the way to the bottom. In some sites the rebar cage is installed first and concrete is poured around it. The piles will stick out of the ground and an eight-inch-thick concrete slab will be poured around and over them, with rebar throughout, said Clint Bjella, project manager for general contractor Allied Construction of Everett.
This basically ties it down to solid ground so its not going anywhere, Bjella said.
The main fear is that in an earthquake the soil underneath the school could liquefy and damage the building, according to Marysville building inspector John Dorcas. A school has to be designed and engineered more thoroughly than many other structures, he said, noting that when an occupant load gets above a certain number additional safeguards have to be put in.
The soil is a little soft there, thats why the engineers designed it with the auger cast piling, Dorcas explained.
District superintendent Larry Nyland said his office has been getting many calls from people asking if crews are drilling for oil at the site.
That building is the safest building in Marysville if there is an earthquake, Nyland told the school board on Aug. 6.

Marysville Getchell High School on track for 2010
Administrators plan on committing the Marysville School District to a 2010 opening for a new 1,600-student high school, according to capital projects director John Bingham. The $79 million high school was the center piece and crown jewel of a $118 million bond package approved by voters in February 2006 and will be designed to accommodate four of the new smaller learning communities opening this fall. Bingham convinced the school board to take advantage of a state program that still uses the competitive bidding process while allowing districts to bring a general contractor on board much earlier.
That gives the general and subcontractors more input on how the building is designed, and keeps architects and engineers appraised of the most efficient techniques they can use. Bids usually come in much lower because subcontractors are much more confident they can do the just as specified, according to Bingham. Savings on past projects for other school districts have approached 20 percent in some cases, and thats especially important as inflation plague the entire construction industry, effecting both materials and labor.
In addition to the new $20 million elementary school, and the new Marysville Getchell High School, both funded with property taxes, the district is also building a new shared options campus for three schools on a site next to Quil Ceda Elementary School on the Tulalip Indian Reservation. That campus is funded by mitigation fees levied on new homes built in the 72-square-mile district, and will cost about $24 million and house 700 students in three independent schools.
Construction crews have already created a huge pile of topsoil and sand at the site on 27th Avenue NE, and much of that will be used for other district projects or sold, according to Bingham. Most of the needed areas on the 40-acre campus have been cleared and crews will be pouring footings and foundations for the modular buildings which will comprise the three main buildings on the shared campus. Those structures will be joined by a 12,000-square-foot conventionally built gymnasium and cafeteria that will be shared by the three tenants when the campus opens this September.
The Marysville Arts & Technology High School was scheduled to move into its new quarters after the beginning of the school year, but delays have pushed opening back at least a month for A&T. The Tulalip Heritage High School and the 10th Street Program, a small middle school, will have to wait until later in the year to occupy their new digs.
The modular buildings for A&T are mostly complete and sitting at the Williams Scotsman factory on Smokey Point Boulevard, Bingham said. They will be trucked to the site and installed starting sometime in the next two weeks, he added.

More in News

Inslee: Stay home for 2 weeks

By Jerry Cornfield and Zachariah Bryan The Herald OLYMPIA — Gov. Jay… Continue reading

Fences have been put up around Marysville playgrounds to keep kids off. (Steve Powell/Staff Photos)
Marysville leaders concerned as (almost) everything’s closing

By Steve Powell MARYSVILLE – Within hours of Gov. Jay Inslee’s… Continue reading


Beware of coronavirus scams SEATTLE – U.S. Attorney Brian T. Moran is… Continue reading

Jennifer Thompson, left, and her father Ron Thompson secure a new remembrance plaque to the Oso slide site gate on Sunday, near Oso. Ron Thompson handcrafts a new plaque for the gate every year. (Olivia Vanni / The Herald)
Community remembers Oso slide victims, survivors

By Ben Watanabe The Herald OSO — The power of remembering the… Continue reading

People gather to pick up special allergy meals before leaving Lakewood High School on Wednesday in Marysville. (Olivia Vanni / The Herald)
Districts taking meals to students since schools are closed

By Stephanie Davey The Herald LAKEWOOD — Children wearing pajamas stood outside… Continue reading

Jon Nehring
Letter about coronavirus from Marysville Mayor Jon Nehring

This is an edited version of a letter Marysville Mayor Jon Nehring… Continue reading

DOUGLAS BUell/Staff Photos
                                Lead cook Keina Gowins with Presidents Elementary hands out free grab-and-go breakfasts and lunches to students and parents outside the school Wednesday. Presidents and AHS serve as central kitchen sites for preparing meals, which starting next week will expand to 12 delivery sites from Silvana to Oso. Right, Arlington Food Bank executive director Carla Gastineau and Mike Simpson, food bank board president and owner of Arlington Grocery Outlet, partnered with the district with their Meals Til Monday program, and gave a woman a box of donated food while at Presidents.
Arlington students won’t go hungry during the COVID-19 school closures

ARLINGTON – Arlington schools are closed through April 24 to help fight… Continue reading

Scott Beebe hands out Chromebooks to people in their cars. (Steve Powell/Staff Photos)
Marysville parents anxious to pick up school materials for kids

By Steve Powell MARYSVILLE – A few days ago Marysville schools… Continue reading

Jon Nehring
Marysville leaders’ trip to D.C. productive

MARYSVILLE – City leaders recently obtained advice on how to get more… Continue reading

Crews will blow garbage into the street and sweep it up over the next few weeks. The city is asking people to move their cars, trash cans and recycle bins when they come around to help them do a thorough job. (Courtesy Photo)
Marysville shuffles workers due to virus, seeks public’s help for sweepers next week

By Steve Powell spowell@marysvilleglobe. MARYSVILLE – From working from home to teleconferencing… Continue reading

Arlington closed until April 24 amid COVID-19 outbreak: what’s next?

ARLINGTON – When Arlington public school leaders met for a special meeting… Continue reading