Engineering reports reveal extent of earthquake damage at Eagle River schools

The Anchorage School District has released engineering reports detailing the extent of damage at Gruening Middle School and Eagle River Elementary by the Nov. 30 earthquake.

The reports prepared by Anchorage firm BDS Architects include an analysis of damage as well as options (and cost estimates) for repairing or replacing the facilities, both of which have been closed since the quake. According to the firm, Eagle River Elementary will cost about $12.1 million to repair and add code and building improvements, while Gruening repairs and upgrades will cost about $23.3 million.

The district and Anchorage School Board have already endorsed fixing both facilities, with the bulk of funding expected to be reimbursed with state and federal emergency funds. An upcoming $59 million bond before Anchorage voters includes $4 million for earthquake repairs and funding for a new roof at Eagle River Elementary.

At Eagle River Elementary, most of the worst damage occurred in the gym, which has serious wall damage. At Gruening, shifting steel columns caused broken block walls, the roof is dislodged from the walls in two places, the east stairwell has shifted and there are cracks in the masonry throughout the building. Both buildings also need seismic upgrades.

The largest cost at Gruening will be $6 million to replace the roof. Other major costs at the middle school include $2 million to repair the cinderblock masonry (CMU) on the interior and exterior of the building; $1.2 million for vertical reinforcing of the CMU walls; and $1 million to stiffen the floors surrounding the gym. At Eagle River Elementary, the largest costs are expected to be $2.3 million to replace the roof; $1 million for new branch conduit and wiring; $1 million to improve the main entry and building security; $500,000 for hazardous materials mitigation; and $400,000 to replace the brick veneer with metal panel.

Fixing both schools is expected to take two years. The estimated cost to demolish and replace Gruening would be about $77 million, while tearing down and rebuilding ERES would cost about $35 million.

Both Gruening and ERES are known to contain asbestos and other hazardous materials that “will likely have an impact on the planned renovations,” though no survey has yet been performed, the firm wrote.

Old school held up well

Eagle River Elementary has a capacity of 462 students and at the time of the quake housed about 415 students in preschool through sixth grade -- including two special-education pre-kindergarten classes and an Open Optional program. The building on Old Eagle River Road in downtown Eagle River is 58,086 square feet and was built in 1961, with an eight-classroom addition built in 1962 and major add-ons in 1970 and 1984.

Despite the age of the building, most of it performed well in the quake -- especially those parts that had already survived the much larger 1964 earthquake.

“With two major exceptions, the structure withstood the recent 7.0 magnitude earthquake well,” the firm wrote.

Those exceptions are the north and south walls of the 1984 addition, which became disconnected from the roof in the November quake.

“When the walls became disconnected from the roof diaphragm, they deflected outwards and caused some veneer block to become dislodged. There are also some vertical cracks in the masonry at the classroom vestibules between the corridor wall and the wall perpendicular to the corridor,” BDS wrote.

In addition to the dislodged veneer, there are cracks in mortar joints, inadequate connections between the walls and roof.

The firm also found several broken windows, sporadic cracks in classroom walls and damaged drywall. The building’s suspended acoustical ceilings were “severely damaged/compromised” in the classrooms in the 1984 addition, with dislodged tiles in the older classrooms. There are also cracks in interior concrete walls, though the firm deemed those “cosmetic in nature.”

The “most severe damage” was in the gym area, which was part of the 1984 addition. Along with the wall damage, the floor is buckling in several spots and there’s earthquake debris and hairline cracks throughout.

The firm did not inspect the roof because it was covered in snow, but did find leaks that were likely caused by the quake. However, the roof was already due to be replaced and funded by a bond package currently before Anchorage voters.

Students from the school were split between Birchwood ABC Elementary, Homestead Elementary and Ravenwood Elementary after the quake, but the school district has rezoned Eagle River to split displaced students between Homestead and Birchwood ABC next year, with students in the optional program moved to Fire Lake Elementary.

Gruening needs major repairs

Gruening was built in the early 1980s. The school was originally supposed to open in 1983, but extensive problems related to the design of the school’s roof and seismic capability delayed its opening until 1984. It’s a 124,862-square-foot building with a capacity of 727 students and at the time of the quake housed about 587 students in seventh and eighth grades.

Engineers found major structural damage, including broken block from shifting steel columns within, a failed connection between the southwest wall and roof, a shifted stairwell off the gym and cracked masonry walls “throughout the building at discontinuities, levels and wall intersections.”

The school also has cracked cinderblock walls, cracked drywall, dislodged suspended ceilings and ceiling panels, shifted sprinkler heads, damage to heating and ventilation systems (including shifted water heaters) and numerous instances of miscellaneous damage throughout ranging from a shifted shower pan in the coach’s restroom to pipe hangers no longer attached to the ceiling.

In 2015, Gruening scored 4 on a 1-to-10 seismic performance objective scale -- one notch below the level classified as “life safety.” A 6.5 is the target performance objective, engineers wrote. Gruening was downgraded to a 3 after the quake.

“This puts the building well below the Life Safety (LS) performance objective (5), and the target performance objective of Damage Control (DC, 6.5),” the firm wrote.

After repairs and seismic upgrades are made, the wood-and-concrete structure can be brought up to a 6.5 on the scale, the engineers believe. According to the report, few buildings are rated as high as 10 (or “operational”) on the scale.

“While it would be nice to have all buildings perform to the (operational) level in every earthquake, it is economically and operationally unfeasible to make this happen,” they wrote. “Therefore, only high importance buildings with high risk of loss of life are classified as such.”

The engineers also looked at the geotechnical issues at the location, a 20-acre plot at the end of Lee Street that’s leased from Eklutna Inc. The report said the ground floor appears to be “very close to the elevations established during the original construction,” though elevations taken from the mezzanine surrounding the gym floor “do show elevation deviations greater than those expected.” The damaged stairwell also “shows measurable movement at the second-floor landing.”

As for the site itself, contractor Golder Engineering “could not identify any changes that occurred in the site grading and foundations after reviewing historical data of the site and surrounding area.”

Gruening students have been attending classes at Chugiak High, which has a capacity of 1,618 but only held 886 students when the quake struck.

To view the full reports, visit asdk12.org.