The consulting firm hired to review plans for the new Cal State Northridge parking garage, which collapsed in last month’s earthquake, warned Cal State system officials that the design did not meet seismic strength standards in the building code, public records show.
Esgil Corp. of San Diego told Cal State system officials in September, 1990, that the garage was designed for effectively half the seismic resistance the builder claimed, concluding that the interior columns were not adequately interconnected with the concrete slab floors and beams.
But system officials decided to go ahead with the project after the construction firm, A. T. Curd Builders of Glendale, solicited letters from five structural engineers supporting its interpretation of the building code, the records show.
Cal State officials did not question the experts themselves but relied on Curd to contact them and relay their opinions.
The garage, completed in July, 1991, partially collapsed during last month’s earthquake.
And as the failed parking structure has further crumpled in the swarms of aftershocks, the slumping concrete-and-steel ghost--its middle is still standing--has become what Curd acknowledges is the “photographic icon” for destruction wrought by the temblor.
Curd has stated that the structure met and exceeded all building codes.
W. Clifford Hahn, Cal State’s principal engineer who supervised construction, defended the university’s actions as prudent. Hahn works at the university system’s construction management division, which is located in Seal Beach and is responsible for bidding and overseeing of major capital projects at Cal State’s 20 campuses.
Hahn said officials also had to balance earthquake concerns against project delays and the fear that the builder would file a monetary claim for holding up construction, which it ultimately did. He also said letters supplied by Curd from other structural engineers convinced him and his immediate supervisor--John Stopforth, chief of the Cal State construction management unit--that Esgil was being too conservative in its interpretation of the building code.
But Cal State project records show that Esgil--hired specifically by the system to make sure building plans conform to building codes--expressed strong misgivings about the garage’s ability to absorb the seismic forces that builder Curd claimed.
Esgil’s objection was so serious that, at one point, foundation work was halted for 19 days and the construction firm was forced to lay off laborers before university officials persuaded the San Diego firm to modify its position and allow the project to resume, records show.
“We changed it because our client changed it for us,” said Manuel Ainza, a former Esgil structural engineer who supervised the plan check of the Northridge garage.
Both Ainza and Ali Sadre, the Esgil structural engineer whose name appears on Cal State plan check documents, said the firm’s interpretation of the 1988 Uniform Building Code would have required Curd and Cal State to strengthen interconnections among the interior columns.
“It’s like designing a ladder for a 300-pound man, as the code requires, but you (actually) design it for a 150-pound man,” Sadre said. “When a 200-pound man goes on it, it’s going to break.”
Sadre told The Times that he was so “stressed” about how his plan check was handled by Cal State that he refused to sign off on the project, leaving the matter up to Ainza and other Esgil managers.
“I always had thought that if someday we had a major earthquake this would be a building that would be in trouble, but I never thought in my lifetime we would see something like this,” Sadre said. “What are the possibilities that a building like this, so new, would be in the middle of a seismic event?”
Hahn now says he intends to relay Esgil’s warnings to experts investigating the garage collapse, as well as supply them copies of documents obtained by The Times this week. It is up to them to determine whether the earthquake proved Esgil correct, he said.
“I will be raising the question,” Hahn said. “Obviously, we need to know the answer.”
So far, there is divided opinion on what buckled the garage, on Zelzah Avenue about two miles from the earthquake’s epicenter. Some believe it was the temblor’s unusual up-and-down motion, virtually unanticipated by building codes, that crushed the precast concrete columns. Others say it was an earthquake’s more typical sideways force that knocked the columns over like bowling pins.
On Wednesday, Curd released a 20-page report blaming the vertical forces for “exploding” the columns, which were crunched three to seven feet and allowed the weight of the concrete walls to fall inward. President Andrew T. Curd wrote that the Cal State Northridge garage was built “to meet and exceed the standards established at the time of design and construction.”
In a section entitled “New Design Measures,” the Curd report says that further seismic bracing can be “achieved by adding vertical and horizontal reinforcing steel to the gravity (interior) columns.”
Curd said in an interview Thursday that putting more steel inside the columns is different than the stronger connections that Esgil wanted at the joints of the interior columns. Esgil’s measures would not have saved the structure because connections only absorb back-and-forth motions and not the vertical jolt of last month’s earthquake, he said. The Curd report does not mention the warnings by Esgil.
Cal State’s handling of the Northridge garage project underscores what many engineers have said--that the building code, contrary to public belief, is a minimal standard open to interpretation.
The Northridge garage history raises questions about a system that Cal State officials say guarantees that independent experts double-check their campus construction projects.
The need for such reviews was dramatically highlighted by the 1990 collapse of the 120-ton roof on Cal State Long Beach’s music complex. A study found that the roof was constructed at a time when Cal State officials relied on project architects and engineers to find and correct their own mistakes.
Since the 1980s, Cal State has hired firms such as Esgil to serve as plan check consultants. The San Diego firm--which also advises 71 other cities, counties and state agencies--reviews construction plans for all but two of the university’s Southern California campuses.
Thus, it fell to Esgil to review designs for the Northridge garage when officials elected to go through with the project at the burgeoning San Fernando Valley campus. In April, 1990, Whiting-Turner Contracting and its principal subcontractor, Curd Builders, won the bid with its proposal to build a 2,646-stall structure for $11.3 million and in 374 days.
Andrew Curd said in an interview that his firm scored the most points in the bidding because of the garage design. He said the design called for tying together pre-cast concrete pillars and beams to form a three-dimensional box.
The design, he said, not only leaves no hidden corners in which attackers can lurk but also is “flexible in an earthquake.” A steel-reinforced “ductile” frame is supposed to absorb shocks by bending but not breaking under stress, said Curd and structural engineers.
Because of those qualities, Curd’s company considered its garage to be what the building code calls a “moment resisting frame building"--meaning that its joints were able to take that back-and-forth punishment, or “moments,” expected from an earthquake. The 1988 building code gave such buildings a load-carrying capacity value of 12, a number that allows building materials to be lighter--and less expensive--because the structure is expected to bend.
But in August, 1990, Esgil’s Sadre took exception to that, records show. And in his September, 1990, plan check report, Sadre assigned the garage a value of 6, which is reserved for less flexible buildings, records show. The reason: The precast system did not have adequate ability to flex but not break where the interior columns met the beams and floor.
Records show that Sadre based his interpretation, in part, on the so-called Blue Book commentary, written by the Structural Engineers Assn. of California, to clarify the intent of code provisions. By choosing a value of 6, Sadre asserted the building was only half the strength that Curd had claimed, and should be redesigned.
Sadre’s objection caused immediate problems. In a Sept. 27 letter, Kent Jessen, an engineer for Curd, wrote that the issue “is of major significance, as this is how the code determines the magnitude of the design forces to account for earthquake loading.”
“We respect Esgil’s right to have their own in-house design criteria, no doubt based upon highly reputable sources, and we believe it is honorable that they use what they interpret is correct in the design of their own projects,” Jessen wrote. “However, these interpretations, when not clearly defined in the code, cannot be forced upon other designers, who may very well have their own interpretations.”
Two days later, Whiting-Turner--the project’s general contractor--wrote to university officials complaining about Sadre’s “unfair interpretation” and asked for a meeting. “As you are aware, the impact of this review comment is severe with respect to schedule delays and construction costs,” wrote Paul Schmitt, Whiting-Turner’s manager for the project.
Whiting-Turner, Curd and its engineers argued that the design met the code and that the commentary, while it recommended stronger connections for the interior columns, did not impose any legal requirements, records show.
At first, Cal State system officials asked Esgil and the construction firm to resolve the dispute, but Sadre said it was impossible. “We could not come up with an agreement because it was black and white, there could be no compromise,” Sadre said. “It was like we were calling it (the design) a car and they were calling it a boat.”
Given the stalemate, Hahn said Cal State officials leaned toward Esgil’s opinion but agreed with Curd’s suggestion that the dispute be decided by other engineering firms.
“We had no ax to grind,” Hahn said. “We would have gone with our plan checker if they (Curd) had not sought the tie-break. . . . It was a reasonable way of breaking a tie; we’ve done it before.”
Hahn said such a peer review is not unusual on major construction projects, including disputes with Esgil, which he said is known to be conservative in its interpretation of the code.
Records show that Curd provided Cal State officials with letters dated Oct. 3 and 4 from five engineering firms. American Structural Engineers of Long Beach, Sven Sorensen Inc. of Blue Jay, and Johnson & Nielsen Associates of Los Angeles supported Curd’s contention that its design rated a 12, files show.
On Thursday, Sven A. K. Sorensen, the company’s president, said Curd solicited his opinion because they had worked together on a number of parking garage projects. Asked if he was paid to review the matter, Sorensen replied: “I can’t comment on whether Curd paid a fee. . . . Obviously, I don’t do something like that for nothing.”
Since the dispute, Curd has also hired the Las Vegas affiliate of Martin & Associates to build the MGM Grand Hotel, and American Structural to design two parking garages Curd built in Las Vegas and in Los Angeles, said Curd vice president David Anderson.
Hahn said Cal State officials never contacted the firms directly, did not check to see if they had current or potential business ties with Curd and did not offer to pay for the opinions about the dispute.
Records show that Esgil would not back down from its interpretation, however. Letters show that Esgil told Whiting-Turner on Sept. 17 that it saw the issue as “more than a code clarification and that they would insist on enforcing their position on the review comment.”
Cal State officials still had the responsibility to decide, and records show that Hahn and his supervisor, Stopforth, called Esgil on Oct. 16 to discuss the matter. In his handwritten notes, Hahn wrote about the conversation:
“Esgil will state (recommendation) to comply with Blue Book but agree design complies with code. CSU can then concur to not require additional (non-contractor design enhancement).” Nine days after the conversation, Esgil submitted a second plan check list that noted its original objection over the seismic rating had been “resolved by CSU/Esgil mutual agreement.”
“Our client said, ‘We’re going to go with the strict letter of the law.’ We said, ‘Well, you’re the client. We’ll do what you want to do,’ ” said Ainza, who was laid off from Esgil two years ago and now works for another structural engineering firm in San Diego.
Asked if the firm was pressured into relenting, Esgil President Richard Esgate said, “Absolutely not.” Esgate said his firm acts only in an “advisory role” and has no regulatory authority over Cal State.
Hahn said part of the reason Cal State officials eventually sided with Curd was that they did not want to risk further delay of the project, tempting the builder and its general contractor on the job to sue the university for damages.
“It’s not in our normal role to second-guess, to doubt that, make it stronger than code,” Hahn said. “That’s not something we normally do. You can second-guess this, you can Monday-morning quarterback it. You can be a whole lot smarter after an earthquake, but at the time we believe we acted prudently.”
Times staff writer Myron Levin contributed to this story.