Experts Find New Flaws but Call Subway Tunnels Safe

Specialists hired to examine the Los Angeles subway reported Wednesday that they found lax enforcement of construction requirements, along with previously undiscovered areas of thin concrete, air pockets and missing reinforcing steel in the tunnel walls.

But the engineers who assessed the structures said the tunnels are safe and will remain so if the air pockets are filled and leaks of corrosive water are sealed.

Franklin E. White, chief executive officer of the Metropolitan Transportation Authority, said he will seek to have the contractor whose work was found most defective, Tutor-Saliba Corp., perform or pay for the repairs.

White and MTA Chairman Richard Alatorre said they also will try to force Parsons-Dillingham, the management firm paid in excess of $170 million to oversee subway construction, to share repair costs.

White said he does not know what the repairs will cost.

“There were some shortcomings in the construction,” White said. “There were also some shortcomings in the supervision of that construction (by Parsons-Dillingham). But again, the key point is that the tunnel, despite those conditions, (is) safe.”

Ronald N. Tutor, president of Tutor-Saliba, said that although he believes his company has been unfairly singled out for scrutiny, he would make the repairs.

“I expect to look at the report, and wherever these areas of (air voids) occur, we’ll fix them,” Tutor said, adding that deficiencies would be found in any structure scrutinized like the 1.8 miles of twin tunnels built by his firm between Union Station and Pershing Square.

Citing a need to review the findings in more detail, the MTA board of directors postponed a vote on final approval of a new $45-million construction contract for which Tutor-Saliba is the low bidder.

A Parsons-Dillingham spokeswoman said the firm will try to cooperate with the MTA but has not yet agreed to pay for repairs. “We’re willing to sit down with them and figure out what we can do,” Debra Fox said.

Another representative of Parsons, Ray W. Judson, said in a statement that the firm has “put into place an entire new management team” that is doing a better job on the construction of new segments of the Red Line subway.

The reports unveiled Wednesday were prepared by two separate groups hired in September in response to an article in The Times reporting that numerous sections of the concrete subway tunnels were built thinner than the design-specified thickness of 12 inches.

One group of two engineers and a former tunnel company executive examined the physical soundness of the tunnels and produced a 45-page report. The second group, a New Jersey-based law firm that specializes in engineering matters, examined the performance of Parsons-Dillingham in overseeing construction and managing costs of the $1.45-billion subway, including the handling of contract amendments called change orders. The firm found that the shortcomings of Parsons-Dillingham were extensive.

“Concrete was placed in some instances without inspector approval,” the engineering law firm, Barba Arkon International Inc., said in a 49-page report. “(We) also identified significant deviations from (Parsons-Dillingham’s) written procedures relative to stop work notices, change order analysis, project scheduling requirements and quality assurance/quality control procedures.

“These deviations from written procedures are at variance with what is considered acceptable industry practice.”

Evans M. Barba, chairman of the law firm, said his investigation found that the worst problems occurred in Parsons-Dillingham’s management of the construction between Union Station and Pershing Square. Barba, whose firm was paid $150,000, identified seven categories of “substantial deviations” from contract specifications.

The law firm was generally more pointed in its conclusions than was the separate panel of three experts hired to review the soundness of the tunnels.

The panel and its team of consultants, who were paid a total of $1.25 million, identified at least 350 linear feet of previously undiscovered thin concrete and air voids in the crown areas of the tunnels between Union Station and Pershing Square. The panel recommended that the voids, located between the concrete and a plastic membrane designed to keep the tunnel dry and gas-free, be filled with injections of grout. The voids, ranging in width to six feet and in length to 20 feet, are serving as conduits for water that has been leaking into the tops of the tunnels, the panel said.

After conducting tests, the panel concluded that the new areas of concrete thinness--along with areas of missing reinforcing steel--are of no structural significance.

The contract specifications called for 12 inches of concrete, and officials have required contractors to place extra rods of reinforcing steel in areas where thickness dips below 10 inches.

The tunnel panel found that Tutor-Saliba had not placed extra reinforcing steel in the areas of newly discovered thin concrete. The experts also determined that workers had severed the rods of steel at certain construction joints, contrary to design plans that called for continuous steel reinforcing.

However, the panel members said tunnel walls that are at least six inches--with no rods of reinforcing steel--are adequate.

The panel was made up of Edward J. Cording, an engineering professor at the University of Illinois; John M. Hanson, a retired executive and professor of engineering at North Carolina State University, and Paul De Marco, a retired tunnel company executive from New Jersey.

In an interview, Hanson and Cording said they were unconcerned about missing reinforcing steel because they concluded that the steel served no role in providing structural strength. That conclusion drew immediate reaction.

“I’m flabbergasted,” said Michael L. Shank, whose Colorado-based company built the subway tunnels between Pershing Square and MacArthur Park.

He said his firm was required in all instances to place extra steel in any area of thin concrete. “We were just saps,” Shank added. “All I can say is, they held us to a different standard.”

John F. Hall, a professor at Caltech who specializes in earthquake engineering, said he, too, was surprised. “We don’t just put steel in tunnels to make ourselves feel good,” Hall said.

He noted that the panel’s report acknowledged that the reinforcing steel was required at the time of construction, partly “to provide bending capacity for ground loads.”

James Pott, an engineer and former board member of the MTA’s rail construction subsidiary, said the tunnel panel’s conclusion that the structures would be adequate with six inches of concrete, with no steel rebar, is a “complete override of everything that’s been designed. Why bother with these construction requirements?”

In addition to calling for repair of air voids and water leaks, the panel said that:

* Because “grouting records are not available,” the MTA should determine the extent of other voids between the plastic membrane and the surrounding earth and fill them.

* The Northridge earthquake widened some tunnel cracks, and transit officials should consider repairs to “prevent further separation of cracks” that would allow pieces of concrete to crumble onto the tracks from the entrances to utility rooms.

* Some water leaking into the tunnel is highly corrosive, and it should be monitored “with the aim of detecting changes in conditions at an early stage and grouting or making (other) repairs.”

* MTA officials should examine a defective concrete wall along tracks outside the Civic Center station to “determine whether additional work needs to be done.”

Board members of the MTA were divided Wednesday in their responses to the reports. The findings allayed the fears of some, but heightened the concerns of others. Some officials said the reports proved that the MTA must exercise far more diligent oversight of its multibillion-dollar projects.

“When you pay for a system you pay for it to be delivered in operating, Class A condition--not with deficiencies,” said county Supervisor Mike Antonovich. “It’s the equivalent of buying a new car and finding (that) the engine, the tires and the transmission go out when you drive it off the showroom floor.”

Long Beach Councilman Evan Anderson Braude said: “It confirms my feeling that the tunnel is safe.”

Subway Tunnel Inspection

A panel of experts concluded Tuesday that some tunnel walls in the Los Angeles subway were built thinner than designed but are structurally sound. The panel also found the Red Line subway was built with some voids between the concrete tunnel liner and a plastic membrane that surrounds the tunnel. The gaps are up to six feet wide, 20 feet long, and 33 3/4 inches deep. The experts recommend repair of 18 gaps between Pershing Square and Union Station.