A city panel of engineers says a major study that confirms flaws in both the design and the construction of the Port of Anchorage expansion project appears thorough and on target in terms of a technical assessment.
The city's Geotechnical Advisory Commission has been seeking an independent review of the port design for years. At a meeting Tuesday, some commission members said the year-long $2.2 million study by CH2M Hill satisfies that goal -- a bit late. Three of the four new sections already built were not constructed correctly but even if they were, they risk failure during an earthquake due to shifting earth, CH2M Hill engineers said last month in a briefing to the Anchorage Assembly.
The city doesn't yet know how it will fix the troubled project and complete the port replacement. Will flawed new sections have to be ripped out? Will the city have to start over with a new design, after more than a decade of work? A second, $500,000 study by CH2M Hill is under way to lay out options.
The commission was asked by the municipality to review the 2,200-page study, still in draft form, and make recommendations before it is released publicly. The nine engineers on the panel came up with 12 pages of tweaks, questions and comments still being fine-tuned. The commission intends to complete its analysis of the port study by Dec. 20, and the study itself will be released at some point after that.
"I can't think of anything geotechnically-related in terms of what we were asking for in an independent review that wasn't at least touched on," said Robert "Buzz" Scher, one of the commission members.
One area CH2M Hill didn't address -- and wasn't asked to look into-- was why the port selected an unconventional design and whether it should have. Instead of a traditional dock on piling, the new port is designed as a series of U-shaped steel cells backfilled with gravel and dirt to create new land. Many of the steel sheets, which hook one into the next, were damaged during installation.
One weakness of the port design, commission member David Cole and others said, is the lack of back-up systems to hold the structure in place if one part fails.
"You unzip one of these things and things start falling apart," Cole said. "You've got a pile-supported dock. If a pile fails, well yeah, you have an issue, but the whole thing doesn't fall down, necessarily."
The project designer, PND Engineers Inc., has said its patented Open Cell Sheet Pile system has been built successfully around the world, and that it will work at the Port of Anchorage.
But some of the steel sheets driven into the seafloor for the Port of Anchorage project were especially long, and the taller the wall, the greater the risk of failure, CH2M Hill found. In one section, steel walls 89 feet high formed the new dock face, leading to a "factor of safety" with almost no room for error, the study said.
Former Gov. Bill Sheffield was the port director until his January retirement, and he latched onto the PND design to gain acreage at the urban port on Anchorage's northern edge.
"I remember Gov. Sheffield's eyes lighting up when he heard about the idea," Scher said.
The CH2M Hill study didn't examine why the design was picked or whether the new acreage is even needed, and those are important questions for such a critical piece of infrastructure, commission members said. Almost everything sold in Alaska comes through the port.
The report says "an earth-filled bulkhead structure was selected," according to a draft of comments submitted by individual Geotechnical Advisory Commission members.
"Who made that decision? What were the selection criteria? What studies were done to determine the alternative's pros and cons?" the draft says. "Those questions are important because the public will have no confidence that in the future the new selection is better."
The political element needs to be recognized so that the same mistakes don't happen again, the draft said. Engineering criteria, not political considerations, should drive the design.
The project has cost more than $300 million so far, much of it from federal earmarks. No matter what happens with the design, the port gained land and new roads, utilities and a rail line, the city has said.
It wasn't clear Tuesday when the full study will become public. Mayor Dan Sullivan has said that won't happen until the commission completes its work. Highlights were presented to the Assembly Nov. 9.
The city initially intended to release the study Dec. 18 but the Geotechnical Advisory Commission asked for additional time to review it.
Reach Lisa Demer at firstname.lastname@example.org or 257-4390.