Upgrading seismic resiliency at the Port of Alaska
Repair work to earthquake-damaged piling at the Port of Alaska is wrapping up ahead of winter, and port managers are looking at what comes next.
Engineer inspections performed after the 2019 snow melt revealed more damage than port managers could see in the aftermath of the earthquake. They found that 20 percent of piles holding up POL2, a dock receiving petroleum, oil and cement imports, had failed. This failure was so severe that the port had to de-rate the loading capacity of the dock while making repairs.
“We didn’t have to shut the dock down entirely,” said POA External Affairs Director Jim Jager. “But it did reduce the amount of goods brought in through the dock.”
POL2 piling repairs consisted of wrapping custom fit metal “pile jackets” around about 60 structurally compromised supports, according to Jager. The piling was already well beyond its lifespan before the earthquake and had been weakening due to corrosion.
The municipality has been spending about $3 million per year on these pile jackets to prolong the lifespan of port pilings, however they only add 10-15 years -- effectively “kicking the can down the road.” The jackets do little to increase seismic resiliency of the vulnerable port infrastructure, according to Jager. He argues that docks should be upgraded to better withstand seismic motion.
"Because we bring in so much of the fuel and cement used in the state, we really need to make sure that those facilities are resilient and operational," Jager said.
Jager says some of the port docks were built in the early 1960s, and currently do not meet modern minimum seismic standards. He says the discussion around upgrading seismic standards centers around cost -- building docks to higher seismic standards costs anywhere from 10 to 15 percent more money than meeting minimum standards.
“In order to build a new dock, we have to be able to hit what’s called a life and safety standard,” Jager said. “What that basically says is that if you’re on the dock when the earthquake hits, the dock may not survive, but the people survive.”
“The question should really be, ‘Because our docks are so important to our economy, and to Alaska’s economy, should we build to a higher standard so that
the dock survive?” he continued.
The Port of Alaska Modernization Program has always looked to replace aging infrastructure and to improve seismic resiliency. But Jager questions how much money the municipality can generate to pay for the significant seismic upgrades that port managers recommend?
Whatever decisions are made, the POA website makes one thing clear:
“Today, after more than half a century of reliable service, the facility is suffering a slow-motion disaster from corrosion and age, and the docks are unlikely to survive another significant earthquake,” it reads.