MTA Delayed Response to Warning on Tunnels : Subway: To save money, they say, officials waited six months before ordering contractor to stabilize ground.

Nearly a year before subway construction beneath Hollywood Boulevard caused the street and adjoining buildings to sink, officials were warned that settling would occur unless the contractor altered its tunneling technique.

But records and interviews show that Los Angeles transit officials waited six months before ordering the contractor to begin stabilizing the ground with grout.

Even so, more than 100 yards of the area that sank last month had been excavated without the grouting required by the subway contract, according to inspection reports. The sinking in Hollywood broke water lines, crumbled parts of the Walk of Fame and damaged buildings from Vine Street to Highland Avenue. Vehicle traffic, halted Aug. 20 and 21, remains restricted.

The Metropolitan Transportation Authority has not assigned blame for the sinkage, which is expected to prompt millions of dollars in claims from property owners and repairs to tunnels.

Officials said that the grouting initially was not conducted along Hollywood Boulevard and Vermont Avenue out of a desire to save money. They said that they believed other aspects of the tunnel construction would adequately stabilize the soil.

An aide to the MTA’s chief executive officer, Franklin E. White, said that he is generally satisfied with the construction decisions that have been made--but will withhold more definitive judgment until after the Federal Transportation Administration completes an ongoing review.

“There is a responsibility to be determined here,” said the aide, L.A. (Kim) Kimball. The MTA will pay for remedial work now under way but may later ask other parties to assist, he said. The agency’s first focus, Kimball said, is to ensure that tunneling can be resumed safely.

Representatives of the contractor, Shea-Kiewit-Kenny, a joint venture controlled by the Walnut-based J. F. Shea Co., declined to discuss the tunneling. The contractor has notified the transit agency that it attributes the sinking to unexpected underground conditions.

Ground sinkage once was a frequent consequence of tunneling projects. But with the advent of modern techniques--including the use of grout--settlement of more than one inch is generally considered unacceptable. Parts of Hollywood Boulevard sank up to nine inches.

The sinkage is but the latest difficulty for what already is the most expensive subway project per mile in U.S. history. The project’s first tunnel walls were built thinner than designed by another contractor. And according to an independent review, the MTA’s construction management firm conducted substandard inspections.

Officials had pledged improved quality and oversight for new construction. A proving ground for these efforts was to be the roughly 12 miles of twin tunnels from Wilshire Boulevard north to Hollywood Boulevard and west to La Brea Avenue.

The $165-million contract won by Shea-Kiewit-Kenny, the largest on the subway project, is expected to exceed $200 million because of the sinkage and earlier construction difficulties.

When tunneling was just under way in June 1993, MTA rail construction President Edward McSpedon voiced optimism about his ability to control the cost and quality of the work. He said the transit agency was spending more for soil borings to prevent contractors from claiming that they encountered unexpected conditions underground.

“We believe that the investment in more borings will more than pay for itself, many times over,” McSpedon said in an interview. “We have poked more holes in Vermont Avenue and Hollywood Boulevard than a pin cushion . . . The more information you have, the smarter you are.”

One month later, on July 8, 1993, tunneling operations came to a halt when underground water flooded the excavation at the eastern end of Hollywood Boulevard. Tunneling ceased until January 1994, while the equivalent of a small town’s water supply was pumped into storm drains.

The project fell nine months behind schedule as a result of the flooding and a three-week closure, ordered after scores of alleged worker safety violations were uncovered.

Meanwhile, an MTA engineering consultant, Paul Eller, warned McSpedon’s staff in an October, 1993, meeting that they should enforce a specification requiring “contact grouting” of the tunnels. Eller, The Times has learned, said he believed that irregular ground subsidence already was occurring above the tunnels on Vermont Avenue.

John Adams, vice president of construction for the MTA, said that he and others rejected Eller’s advice. Adams said he believed that contact grouting was unnecessary because the same, ground-stabilizing benefits could be gained through other procedures.

Reached recently, Eller declined to discuss his advice, saying: “This is going to come to a head at some time.”

Contact grouting entails the injection of grout into the soil from within each freshly dug, circular section of tunnel. It is designed to help prevent sinking by ensuring tight contact between the concrete tunnel liner and the ground.

The specifications for the Vermont and Hollywood tunnels required the contractor to grout within 16 hours of each four-foot advancement of the tunnel boring machine.

Shea-Kiewit-Kenny had proposed at the outset of tunneling that contact grouting be eliminated. One MTA official said that up to $1 million could have been saved if none of the grouting had been required.

Although tunneling ensued without grouting--and as data showed sinking along both Hollywood and Vermont--McSpedon’s staff delayed deciding whether to require the grouting until March, 1994, after roughly one-third of the tunnels had been dug.

After the contractor continued to object to the grouting, Salvatore J. Calvanico, an engineer employed by the MTA’s management firm, Parsons-Dillingham, wrote in an April report that benefits of performing the grouting “far outweigh any minor cost savings.”

Asked why the MTA did not originally require Shea-Kiewit-Kenny to comply with the contract specification, MTA project manager Joel J. Sandberg said: “We have to consider anything that’s proposed” to save money. The tunneling, he said, was allowed to continue on a “test basis” without grouting.

Daily inspection reports show that Shea-Kiewit-Kenny did not contact grout about 340 linear feet of tunnel--a span longer than a football field--between Whitley and Las Palmas avenues.

In addition, inspectors repeatedly noted that they had no way of determining what volume of grout was being pumped. The contract required accurate monitoring of the grout quantities.

“We need a little more consistency in how we’re reporting the tunnel grouting,” Chris Dixon, project manager for Parsons-Dillingham, said in an interview.

By July 27, according to a recent MTA report, Hollywood Boulevard had sunk four inches.

One Parsons-Dillingham inspector, Michael N. Graber, cited the contractor for failing to comply with the tunnel grouting specification, other records show. Graber filed his four “non-conformance reports” on Aug. 3, 8, 9 and 10.

His logs, part of thousands of pages reviewed under the California Public Records Act, separately noted that the contractor’s grout pumping equipment had broken down.

On Aug. 13, a broken waterline flooded the Pacific Theatre, two blocks away. On Aug. 17, an inspector reported “ground loss” in the form of sinking, wet sand near Highland Avenue. At 11 a.m. on Aug. 18, tunneling was halted. On Aug. 20, officials conceded that a nine-block area of the boulevard had sunk by up to nine inches.

Inspector Bud Morris’ log that day captured the concern beneath the ground: At 1 p.m., Morris wrote, Shea-Kiewit-Kenny’s superintendent evacuated his workers, fearing that “the tunnel was caving in.”

Experts who spoke on condition of anonymity said that at the first signs of significant sinkage on Hollywood Boulevard, the MTA could have minimized further settlement by ordering the contractor to inject grout from the ground surface downward.

This process, called “compaction grouting,” is expensive and slows excavation. But it routinely is done when significant surface settlement is feared.

For instance, after sinkage of four inches was detected on Vermont Avenue, Metro Rail engineer Stephen J. Navin on Oct. 28, 1993, ordered Shea-Kiewit-Kenny to conduct compaction grouting from the surface “to arrest this continued settlement,” records show.

And MTA officials now are using compaction grouting to stabilize the soil on Hollywood Boulevard above existing tunnels and in the path of future excavation. Tons of grout have been injected over the past three weeks.

Sandberg, the MTA project manager, confirmed that at least one staff engineer had recommended compaction grouting in late July or early August, when officials learned that the ground had sunk up to four inches.

“It was considered and it wasn’t viewed that it would necessarily be effective,” Sandberg said. Sandberg said he also had to weigh the disadvantages caused by compaction grouting, including a slowdown to tunneling and disruption to automobile traffic.

Sandberg also said that the project’s chief design engineer, Timothy P. Smirnoff, advised him at the time that compaction grouting was not necessary. Smirnoff’s boss, Martin Rubin, said that the engineer and colleagues “determined that grouting would not significantly reduce settlements.” Rubin, commenting on Smirnoff’s behalf, said that other preventive measures were taken, including “more frequent monitoring” by inspectors and adjusting of the tunnel-boring machine.

It was Smirnoff who drafted an MTA “Tunnel Review Board” report that on Sept. 1 recommended the use of compaction grouting, contact grouting and other precautions during the remainder of the tunneling.

The report cited a combination of factors that contributed to the ground sinkage, including the broken water lines and “indetectable” differences in soil characteristics. Records show that one panelist who signed Smirnoff’s report, soils specialist James P. Gould, had told officials in writing Nov. 15 that contact grouting would not be necessary in the loose, sandy soil beneath Hollywood Boulevard if “water problems” were controlled.

Gould said in an interview that he stands by his earlier advice, noting that broken water mains did dampen some of the soil. He said he believes that contact grouting is of marginal benefit if other tunneling procedures are performed properly.

Now, as preparations continue for a resumption of tunneling, members of the City Council are waiting for further assurances that the work can be done safely. On Sept. 2, they authorized city attorneys to seek a court order blocking construction if independent engineering tests do not allay concerns.

“Right now, you’ve got people presiding over a fiasco,” City Councilman Zev Yaroslavsky, who also sits on the MTA board of directors, said in an interview.

“There is not adequate over- sight on the part of (MTA) executives over the construction process. They have got to quit apologizing for the contractors and quit sweeping things under the rug.”

BACKGROUND

The $3-billion Los Angeles subway is being financed with federal transit funds and two half-cent sales taxes approved by Los Angeles County voters. Currently, 4.4 miles of tunnels carry passengers from Union Station to MacArthur Park. The subway is part of a regional transit network that includes aboveground rail service connecting Downtown to Long Beach, the Santa Clarita Valley and the Inland Empire.

Digging Difficulties

Beginning in late July, the surface of Hollywood Boulevard sank several inches immediately after subway tunneling machines progressed westward, 50 feet below the street. The sinking caused closure of the street from Aug. 19 to Aug. 22. The portion is still partially obstructed to traffic.

Segments of one subway tunnel were not stabilized with grout during excavation.

Source: Metropolitan Transportion Authority