- By: M. Scott Carter
- Posted on: February 20, 2014
MOORE – When the storm came, seven students in the Plaza Towers third-grade center sheltered in the hall. At Briarwood, the students and teachers thought the school building would protect them.
Then the tornado hit, and the schools fell.
Instead of offering protection on May 20, 2013, Plaza Towers became a deathtrap, Briarwood a pile of rubble.
Detailed in a soon-to-be-released report for the American Society of Civil Engineers and the Structural Engineering Institute, an analysis of the debris of the Briarwood Elementary School showed that several of the building’s steel roof beams were not attached to the walls, many of Briarwood’s cinder-block walls were not properly reinforced with steel rebar and large portions of the walls were not backfilled with concrete.
Chris Ramseyer, the civil engineer who studied photographs of the Plaza Towers School, said the photographs showed similar problems and raised serious questions about Plaza Towers’ design and construction quality.
Both Plaza Towers and Briarwood were destroyed when an EF5 tornado struck. Neither school had safe rooms. Seven students were killed at Plaza Towers after walls of the third-grade center, a building next to the main school, collapsed. At Briarwood, at least 24 pupils and teachers were injured when the school’s cinder-block walls fell.
“Odds are, if the schools had been built right, the walls would not have fallen,” Ramseyer said.
In addition, construction documents obtained through an open records request show that Briarwood Elementary was designed by a now-defunct architectural and engineering firm whose founders were disciplined for design flaws in other projects.
Briarwood and RGDC
Briarwood Elementary School, at 14901 S. Hudson Ave., is a small complex comprising a central building, classroom buildings, a multipurpose building and storage buildings.
Construction records show the central building was designed in 1984 by architectural and engineering company RGDC, a once-prominent Oklahoma City firm.
RGDC also designed Bodine Elementary School, Westmoore High School, the aquatic center at Oklahoma City Community College, the Oklahoma County Jail, the Federal Transfer Center at Will Rogers World Airport, the Federal Aviation Administration Aviation Records Building and two water treatment plants for Oklahoma City.
But when problems with the Oklahoma County Jail surfaced, RGDC was publicly vilified. In 1996, two of the company’s principals were found guilty of professional misconduct by the Oklahoma State Board of Registration for Professional Engineers and Land Surveyors.
Records show that Donald G. Douglas and Richard D. Gravlin, two RGDC partners, were found guilty of practicing engineering outside their area of competence and ordered to surrender their professional licenses for six months.
The company’s third founder, architect F. Robert Cornell, was found guilty of practicing engineering without a license and was ordered to cease and desist.
The 1984 Briarwood School plans carry Cornell’s architect stamp.
During the trial, engineers testified that RGDC’s plans for the Federal Transfer Center were filled with dangerous errors. Alan Synar, the attorney for the engineering board at the 1996 hearing, said engineers found more than 1,500 mistakes in RGDC’s plans for the FAA’s Aviation Records Building.
The firm restructured after the three founders were found guilty and changed its name to Triad Design Group. Gravlin died in 2010. Attempts to locate Cornell were unsuccessful. Phone calls to Douglas were not returned.
Code violations and construction flaws
Ramseyer, an associate professor of civil engineering at the University of Oklahoma and a nationally recognized expert on the use of concrete, said debris from Briarwood school showed the school wasn’t built to code.
“(At Briarwood) we found one horizontal steel beam that was designed as a support beam for masonry over the entrance to two classrooms,” Ramseyer said. “But there was no connection from the beam to the masonry, anywhere. No connection. The beam was just sitting there on the walls. Only gravity held it in place. Obviously, that’s not being built to code.”
Ramseyer, who also serves as director of the university’s Donald G. Fears Structural Engineering Lab, is one of the authors of the ASCE-SEI report. He was part of the eight-person ASCE team sent to Moore just days after the May 20 storm and charged with examining debris to see what construction techniques did and did not work.
With support from the Federal Emergency Management Agency, Ramseyer and the ASCE group were allowed to examine and photograph rubble from the school.
He said debris from the Briarwood site showed many of school’s walls were built using only short, 4- to 8-inch vertical overlaps of steel reinforcement – rebar – inside the cinder-block cells.
Huge steel I-beams at Briarwood Elementary were not attached to the masonry walls of the school. The beams did not even have attachment holes. (Photo courtesy Chris Ramseyer)
The International Building Code for reinforced masonry requires cinder blocks used in walls to be backfilled with concrete and to be reinforced with rebar overlaps between 20 and 30 inches long.
“We found some rebar overlaps that were only 4 inches long,” Ramseyer said. “And we found some that were 8 inches long. That’s not enough.”
Because the rebar was so short at the base of the walls it acted as a hinge, allowing high-velocity winds to push the walls over, Ramseyer said.
At Briarwood many of the cinder-block walls were not properly secured at the top, nor were they properly attached to the building’s roofing system. In some areas, the trough block, a masonry block designed to strengthen the wall and tie the wall and the roof together, was simply placed on top of the cinder blocks unattached.
“We found trough blocks that didn’t even have the knockouts taken out,” Ramseyer said. “There was no rebar. The trough blocks are there, but there is no rebar or in some cases concrete in them, and they were not properly attached to the vertical rebar system.”
Ramseyer said steel reinforcement, which was supposed to wrap around corners of the walls, didn’t properly extend around the corners.
“You should have special detailing for it,” he said. “Instead, at Briarwood, the rebar ended and didn’t wrap the corner.”
Bill Coulbourne, a Delaware engineer who served as the team leader for the ASCE study, drew similar conclusions.
“There were places in the building that failed that we should have seen more resistance in the building elements,” he said. “There wasn’t a lot of steel in any of the masonry walls. There were not very long splices between metal reinforcing bars.”
Like Ramseyer, Coulbourne questioned the quality of Briarwood’s construction.
“I don’t think we pay enough attention to critical facilities like these in a community,” Coulbourne said. “They are not treated with the time and attention they deserve.”
Coulbourne is the principal author of the ASCE report, which will be published in the spring.
Oklahoma City architect John Joyce had similar concerns. Joyce, a principal with Engineering Solutions, was also a part of the ASCE team.
“The big obvious thing that I saw was the concrete masonry walls,” Joyce said. “They didn’t have as much reinforcing in them as we’d like to see.”
In January, Joyce told an Oklahoma City television station that he was troubled by the quality of the schools’ construction.
“There were definitely some things that you could kind of look at and say, ‘I can’t believe they built it this way,” Joyce said in a televised interview. “They may not have needed a full-blown FEMA shelter to save those kids. Maybe they just needed it a little bit better than what it was.”
Problems at Plaza Towers
The Plaza Towers school, much older than Briarwood, was built in 1965. Like Briarwood, the school received several additions, including a separate third-grade center built in 2005.
Though the school was leveled by the tornado, debris from Plaza Towers was removed before the ASCE team had an opportunity to examine it.
To study Plaza Towers, Ramseyer reviewed photographs provided by storm victims’ families and media organizations. He said the photographs of Plaza Towers’ third-grade center showed problems similar to those at Briarwood.
The photos, he said, showed the rebar used in the base of the walls at the Plaza Towers third-grade center wasn’t the proper length if the school was supposed to have reinforced concrete walls.
Other photographs of the school showed rebar and masonry work that is consistent with reinforced concrete walls.
“The photos I saw show the rebar wasn’t long enough if the building was designed to have structurally reinforced walls,” he said. “That’s why the walls hinged. If the rebar doesn’t go up into the cinder blocks far enough, then the walls aren’t strong.”
Jeff Horn, the assistant superintendent for operations at Moore Public Schools, said the Plaza Towers third-grade center was built by Barbour and Short Construction of Norman.
Telephone calls to Barbour and Short were not returned.
Steel reinforcement a must
Because reinforcement is vital in the masonry walls of public buildings, the building code requires the use of steel rebar inside the cells of cinder blocks at regular intervals.
That code, the ACI 530 Building Code Requirements and Specification for Masonry Structures, requires the use of rebar once a wall reaches 4 feet. The rebar extending upward must overlap another piece of rebar coming from the opposite direction to provide the necessary vertical reinforcement.
The Briarwood school, Ramseyer said, did not meet those requirements.
At Plaza Towers, because investigators did not have the opportunity to examine the debris, questions about the strength of the school’s walls remain unanswered.
Reinforced masonry walls need a mixture of concrete and steel rebar as shown by this illustration. Rebar from the concrete foundation is run horizontal, then angled upward through the open cell of cinder blocks. At the same time, rebar from the top runs downward, placed in the same cell, which is backfilled with concrete. For proper strength the rebar from both the top and the bottom must overlap for at least 20 to 30 inches. (Graphic illustration by Bryan M. Richter)
“If Plaza Towers was designed to have structurally reinforced walls, then there are problems,” Ramseyer said, “because the rebar I saw in photos was too short.”
Ramseyer said steel has been used in concrete since the 1800s.
“Without reinforcement, the only good use for concrete is a sidewalk,” he said.
Though both schools received certificates of occupancy, the quality of each school’s construction has raised questions about the depth of their code inspections.
Because the Briarwood school lies within the city limits of Oklahoma City, it was inspected by Oklahoma City officials. Plaza Towers sits inside the city limits of Moore and was inspected by code officers from Moore.
Both schools are part of the Moore Public Schools district.
David Adcock, the director of plan review, inspection and permits for Oklahoma City, said city inspectors would have examined only Briarwood’s mechanical, electrical, foundation and plumbing in 1984.
“If there was an inspection of the masonry and steel at that time it would have been the responsibility of the architect or the engineer,” he said.
Though masonry and steel inspections are now required, those inspections are not performed by city inspectors. Masonry and steel inspections, Adcock said, would be done by a third party hired by the builder. And prior to 1984, inspections for masonry were not required at all.
“If it is an area that required engineering, such as the masonry, we would not inspect that,” Adcock said.
Today, once an inspection is complete, the inspector is required to submit letters to Adcock’s office certifying the building was inspected and met code requirements. Adcock said no occupancy permit is issued unless his office has letters for all required inspections.
That type of inspection system concerns Ramseyer. He said inspections for public buildings should be tightened and require that a licensed civil engineer be on-site when concrete, masonry and steel work is being done.
“There should be a structural engineer on-site observing the construction,” he said. “There’s too much at stake.”
Danni Dunn-Legg’s son, Christopher Legg, died at Plaza Towers. She said the reports about construction quality make her angry and concerned for other students.
“If they cut corners and they didn’t get things properly inspected and checked and double-checked, then there is no child that is safe,” she said.
Dunn-Legg said the lack of reinforcement in the walls eliminated any chance her son and other students had for survival.
“It didn’t matter that they were in the halls,” she said. “If the ceiling and the walls are stacked like a deck of cards and you remove one element, it falls.”
Dunn-Legg said she was astonished that no one died at the Briarwood school.
“I believe that if the kids weren’t put back into the classrooms and stuck under their desks in the corner of the room, I think more people would have been severely hurt or killed at Briarwood,” she said.
Like Dunn-Legg, Moore Mayor Glenn Lewis said he was disturbed by the engineers’ findings.
Lewis, who went to the Plaza Towers site right after the tornado hit the school, said part of the reason schools were not designed and built stronger was money.
“It takes 20 seconds for that storm to pass through a building,” he said. “You either build it where it holds up or you build it where it doesn’t, there is not an in-between. It’s an odds game. It’s not right, but that’s how it is. I think it’s going to continue to be a money issue until Oklahoma makes it a priority. I’m not saying that’s right. Schools and public buildings should be built the safest way possible.”
Lewis said the ASCE study underscores the need for better building inspections and more storm shelters.
“At Moore we’ve already hired another code inspector,” he said. “We’re getting federal money to make sure that everything we build is bigger, better and stronger.”
Though Lewis has served as mayor of Moore during three of the city’s most devastating tornadoes, his efforts to require storm shelters in multifamily buildings and private homes have failed.
“I’ve proposed storm shelters after each of them,” he said. “I’ve proposed it twice, and twice it’s been voted down.”
Robert Romines, the superintendent of Moore Public Schools, told The Journal Record last year that the schools being built to replace Plaza Towers and Briarwood would have safe rooms. In addition, Romines said, plans for two other schools that were already in the design stage when the tornado hit in May were changed to include safe rooms.
Repeated efforts to reach Romines for this story were unsuccessful.
Preparing for the next storm
Though Ramseyer said few buildings could survive a direct hit by an EF5 tornado, he and other experts agreed that a building with properly constructed outer walls would have absorbed much more energy from the storm and would have better protected pupils and faculty sheltering in the center of the building.
Ramseyer said public buildings and private homes could be designed and economically built to withstand tornadoes at the EF3 range.
“It’s OK for the structure to have severe damage as long as humans can leave the building alive at the end of the event,” he said. “If that’s the case, then the engineer did their job. Our job isn’t to protect the building. Our job is to protect humanity.”
Had both schools been properly built with properly reinforced cinder-block walls, Ramseyer said, those walls would have given occupants a much greater chance to survive the tornado. The Briarwood and Plaza Towers schools, Ramseyer said, didn’t protect the pupils.
Instead, for those who survived, a larger, unseen force protected them.
“As a human, what I see is, God chose to save them,” he said. “Because this structure didn’t. Bless those teachers who tried to protect their kids, because the building just did not do its job.”
For more on this story, including an interview with Chris Ramseyer, please view this report from OETA.
Read the rest of this article and find other worthy stories at journalrecord.com
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