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Reinforcing of Subway Found to Be Deficient : Transit: Fewer than half the ordered repairs of tunnel's construction defects have been done, officials discover.

September 03, 1993|DAVID WILLMAN | TIMES STAFF WRITER

Less than half of the reinforcing originally ordered to correct construction defects in the new Los Angeles subway has been performed, according to transit officials who immediately ordered repairs and testing to determine the structural soundness of the tunnel.

The discovery of the reinforcing deficiencies Thursday led Metropolitan Transportation Authority executives to fire from the project a top construction management official who oversaw completion of the 4.4-mile Red Line.

The MTA's chief executive officer, Franklin E. White, said workers will begin adding steel reinforcing Friday night to one area of the subway where the concrete walls are thinner than designed.

The discovery of the unreinforced locations was made, officials said, after rail construction engineers were directed to search the tunnels in response to a Times article Sunday disclosing that numerous areas of the subway between Union Station and Pershing Square were built with less concrete than specified.

The article disclosed that radar testing one year ago found 2,082 linear feet of tunnel where the concrete may be just 6 to 8 inches thick. The tunnels were designed to be a minimum of 12 inches thick.

Transit officials had said repeatedly that the contractor used steel plating to buttress three areas of thin concrete spanning 90 feet. But officials said Thursday that only 40 feet of tunnel had been reinforced at two, not three, locations.

"Because of the concerns that have been raised concerning the laying of the concrete and the repairs, I'll be announcing a task force of experts," White said in an interview late Thursday.

White said he will name an independent panel of experts to report only to him and MTA Chairman Richard Alatorre, not to the agency's construction management executives or staff. The experts, White said, will evaluate the structural soundness and safety of the tunnels.

White and Edward McSpedon, president of the MTA's Rail Construction Corp. subsidiary, told The Times that they continue to have confidence in the analyses done by staff design engineers, who have advised that the tunnels are safe and should remain in operation.

"There is nothing to be concerned about, structurally, at this point," McSpedon said.

Both executives said the reinforcement, with half-inch-thick steel plates, immediately will be added to a short section of the tunnel. No interruption of train service is expected.

In addition, McSpedon said that corings of the area were to be taken Thursday night to evaluate the concrete's thickness.

The executives said the non-reinforced concrete was found by staff in the tunnel that takes passengers northbound from the Civic Center to Union Station. Any additional reinforcement work will be performed at the expense of Tutor-Saliba Corp., the company that built the $89-million project, White said.

McSpedon said the decision last year to install less than 90 feet of reinforcing steel was approved by Parsons-Dillingham, the firm hired to oversee all subway construction.

Representatives of Tutor-Saliba could not be reached for comment Thursday. They have previously said that any defects in the concrete work resulted from unintentional construction errors.

The Times reported that radar testing one year ago found 2,082 linear feet of tunnel--in 40 locations--where the concrete may be 6 to 8 inches thick. The tunnels were designed to be a minimum of 12 inches thick. McSpedon has said that no more than 90 feet of tunnel needed reinforcement and that the work was completed before the subway opened in January.

On Thursday, McSpedon said that he and his staff had determined that 40 feet, not 90 feet, of the tunnel is buttressed with steel plating. He alleged that subway completion manager Stuart Williams, employed by the construction management firm of Parsons-Dillingham, was responsible for conveying the erroneous information that 90 feet had been reinforced.

McSpedon said that, at his direction, Williams was terminated from Metro Rail on Thursday. Neither Williams nor representatives of Parsons-Dillingham could be reached for comment.

As for the 50 feet of tunnel described previously by MTA officials as having been plated, McSpedon said he believes that only 15 feet may need to be reinforced.

McSpedon also said that, based on the assurances of Metro Rail designers, he is confident that concrete at least nine inches thick will not require reinforcement, even though it is thinner than design specifications.

Much of the area within the 50 feet previously described as plated, McSpedon said, is now believed to be 9 to 10 inches thick. The designers are employed by the firms of Parsons Brinckerhoff Inc., Daniel, Mann, Johnson & Mendenhall and ICF-Kaiser Engineers.

As recently as last week, a top aide to McSpedon, subway project manager Charles W. Stark, told The Times that any area with concrete less than 10 inches thick should either contain extra rods of reinforcing steel, or be reinforced with exterior steel plating.

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