May 16, 2006 in City
Garage barrier imperfect but exceeds code, study says
The concrete barrier that motorist Jo Ellen Savage hit in last month’s fatal accident in the River Park Square parking garage exceeds building code requirements, according to a Seattle engineering firm that inspected the barrier for the garage’s owner.
But that barrier, known as a spandrel, was half as strong as it was designed to be, engineer Richard Dethlefs said.
And while the international building code, which the city has adopted, says a vehicle barrier of that type should be able to withstand 6,000 pounds of force, Dethlefs said “it appears that vehicles are able to impart more than 6,000 pounds of force on the barriers.”
Engineers from the national firm of Wiss, Janney, Elstner Associates were hired by the garage owners to study the concrete barrier that gave way on April 8 when it was struck by a car driven by Savage, of Pullman. The car went off the fifth-floor deck of the garage, crashing onto the ramp below.
A police report concluded earlier this month that Savage was not traveling at a high rate of speed when her car hit the barrier.
Engineers studied the spandrel that broke and other spandrels nearby, all installed when the garage was built in 1974. As designed, the spandrels should withstand a force of 17,600 pounds, they said in a report released Monday by the garage owners.
The spandrel that broke after the crash was not built and installed to the exact design standard, because the reinforcing steel was not set in the right spot. Based on calculations involving the placement of the steel and the thickness of the concrete, Dethlefs estimated that particular spandrel could withstand 8,400 pounds of force.
“It should have been able to withstand a force of 6,000 pounds (of force) which is what the code is,” Dethlefs said in an interview Monday. “What I’ve seen so far doesn’t lead me to think it’s anything other than an isolated incident.”
That section of the garage was built before a building code existed for that type of vehicle barrier. A standard of being able to withstand 6,000 pounds of force was established in 1997 and in effect when the garage was renovated. It remains in effect for the current building codes that were updated in 2003, the engineering report says.
The garage and adjoining mall are owned by Cowles Co., which also owns the company that publishes The Spokesman-Review.
Bob Smith, the chief executive of the River Park Square parking garage, noted that even though the barrier involved in the accident didn’t meet the design standard, it still exceeded the current building code. Because of that, Smith insisted, the garage is safe.
Dethlefs put it a slightly different way in the report: “The vehicle barriers likely provide a similar level of safety as many of the other parking structures in and around Spokane and throughout the state of Washington.”
Smith said he couldn’t answer whether the building codes need to be changed in light of Dethlefs’ comment in the report that vehicles can hit the barriers with more than 6,000 pounds of force.
“Not being an engineer, I can’t address that. The panel exceeds the standards today,” he said.
The garage owners are continuing to evaluate the property for any changes that would be considered appropriate, Smith said.
The report was released in advance of a city building official hearing on the safety of the garage, scheduled for 1:30 p.m. Wednesday at City Hall.
Marlene Feist, a spokeswoman for Mayor Dennis Hession, said city officials were studying the report and “looking forward to a full presentation” at the hearing.