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Engineers say Port of Anchorage design was seriously flawed

Lisa Demer
Doug Playter of CH2M HILL demonstrates how piling sections interlock with one another during a briefing about the troubled Port of Anchorage project for the Anchorage Assembly Friday afternoon November 9, 2012 at City Hall.
Erik Hill
Assemblyman Paul Honeman seeks answers during a briefing about the troubled Port of Anchorage project for the Anchorage Assembly Friday afternoon November 9, 2012 at City Hall.
Erik Hill

A new federally commissioned study has firmly established that the problems with the Port of Anchorage replacement go beyond flawed construction into the project's very design, the Anchorage Assembly was told Friday.

Three of four new sections already built at the Port of Anchorage were not constructed correctly, but even if they were, they risk failure during an earthquake due to shifting earth, top engineers with CH2M Hill told the Assembly.

"If it starts to move, then you've got potential problems. That's what happened in the 1964 earthquake and that's the worrisome thing about the design right now at the Port of Anchorage," Don Anderson, who led the geotechnical team for CH2M Hill, told the Assembly.

He indicated the three new problem sections, which cost tens of millions of dollars, might not be salvageable. But Mayor Dan Sullivan, who has make completing the port project his No. 1 priority, said it's not known whether the work already done will have to be ripped out entirely.

"I think that was intimated," Sullivan said. But perhaps different construction techniques and materials could make the current design more stable, he said.

CH2M Hill did the year-long, $2.2 million study for the U.S. Army Corps of Engineers and the federal Maritime Administration. The engineering company also has been contracted for a second phase at a cost of another nearly $500,000. That work is expected to be completed by February or March 2013 and will lay out options for completing the port project.

The existing structure probably could be made strong enough, said Larry McCallister, director of programs and project management for the Army Corps in Alaska. "The issue becomes ... how much time, how much money is available and what you really want to do to make a usable facility."

The Corps suggested the study after the city asked it to take over management of the project, which had been under the Maritime Administration, a request it is still considering, McCallister said.

The mayor was briefed last month about the study but refused to discuss the findings until Friday after the Assembly presentation. Last month, the Maritime Administration told the Daily News the study suggested the project shouldn't go forward as designed, but didn't provide details.

CH2M Hill's full, 2,200 page report is in draft form and hasn't been released. It won't be finalized and made public until mid-December, after the Corps of Engineers and the city's Geotechnical Advisory Commission review and comment on it.

Assembly members on Friday were hearing the conclusions for the first time. They seemed stunned.

"I am going to go home and cry," Assembly member Patrick Flynn, whose district includes the port, said after the briefing.

Jennifer Johnston, who chairs an Assembly committee that oversees the port, said the revelations were upsetting, but the port is essential and the project must be completed. Almost all of the consumer goods for Alaskans come through it. Two shipping companies unload cargo vessels there twice a week.

The city has been working for more than a decade to replace the 51-year-old port, which is expensive to maintain. The design for the new port is unconventional. Instead of a traditional dock on piling, the design calls for interlocking steel sheets to be hammered into Cook Inlet, hooking together one to the next and forming a series of U-shaped cells backfilled with dirt and gravel.

Many of steel sheets were damaged during installation, Doug Playter, the CH2M Hill project manager on the study, told the Assembly. Some appeared to have hit boulders. Some unzipped, wrecking the structural strength of an intact, interlocked cell.

But even if the steel sheets were installed perfectly -- and a second contractor at the port was able to do that, using different methods -- concerns remain about the earth fill behind the steel shifting in an earthquake, damaging the dock, Anderson said.

Former Port Director Bill Sheffield, who was a one-term governor before moving to other public positions, pushed for the design, saying at the time that he was convinced it would be cheaper and would create new industrial land for the port.

Reached at home on Friday evening, Sheffield said he hadn't been briefed on the study.

"I'm not happy hearing those kind of things. You'll have to look at it and do further study," Sheffield said. "I'm saddened we got in this mess to begin with." He said engineers, construction companies and contractors all concluded it would work.

CH2M Hill took soil borings from the fill already in place and down into the seafloor, Anderson told the Assembly. It sent the samples to labs at the University of Illinois and in Canada to be tested for strength and stability in mock earthquakes.

It compared the behavior of the soil at the port project site -- Bootlegger Cove clay -- with the landslides that resulted from the 1964 earthquake, which at magnitude 9.2 is the second biggest one recorded in the world, Anderson said.

"What we concluded was that the strength of these materials seemed to be behaving very similar to what people had found when they investigated the Fourth Avenue slide," Anderson said.

While the port is at sea level and the landslides in 1964 occurred higher up, on bluffs, the expansion project essentially involves creating artificial bluffs. In one section already built, the steel walls are 89 feet high, as tall as a nine story building.

"Basically these are large earth fills behind that thin sheet pile wall," Anderson said.

The CH2M Hill analysis used different assumptions than a similar assessment by the project designer, PND Engineers Inc., he said. For instance, his team assumed that a big earthquake would hit at low tide, when the structure is most exposed and vulnerable.

Principals of PND Engineers Inc. were out of state and not available to speak to the study conclusions. In a statement issued last week, the company said its patented Open Cell Sheet Pile design was first used more than 30 years ago at Nenana on the Tanana River, a facility still being used today. It has designed some 180 open cell structures throughout the world including four within two miles of the Port of Anchorage.

"These structures are located in environments from the arctic to tropical to extreme tidal ranges and have been subjected to multiple earthquakes without any failures," PND said in the statement.

CH2M Hill -- which has designed or managed port and waterway projects around the world, including the current expansion of the Panama Canal -- noted another issue with the design. The steel sheets, though galvanized to protect against rust, would corrode and after 50 years fall below the specified strength requirements, Playter told the Assembly. Big infrastructure projects today tend to be designed to last 75 years, not 50, he said.

"We inherited something that clearly had gone wrong," Sullivan said of the project, which began under the Wuerch administration, with construction starting when U.S. Sen. Mark Begich was mayor. "I've pledged that during my administration, by the time we leave in 2 1/2 years, we'll be well on our way to a newly constructed port that's going to last us 50 to 75 years."

So far, more than $300 million has been spent on the project but all that isn't money wasted, according to CH2M Hill as well as the city. The port gained 65 acres of new land. Roads were built and a rail line was added. One new section, the dry barge berth at the far north of the port, is considered structurally sound and is in use.

The city has about $133 million still in hand for the project, counting $50 million approved Tuesday in a statewide bond proposition.

But it will need hundreds of millions of dollars more to finish the project, the mayor said.

 

Reach Lisa Demer at ldemer@adn.com or 257-4390.

 


By LISA DEMER
ldemer@adn.com