How Alaska fixed its earthquake-shattered roads in just days

Shaking from the large earthquake that shuddered through Anchorage, Alaska last week was strong enough to turn smooth asphalt roads into broken, jagged depressions of rubble. But within just a few days, crews managed to repair the worst of the damage, unsnarling traffic in Alaska’s largest city.

Anchorage has a population of nearly 300,000 people spread across more than 1,900 square miles — an area larger than the state of Rhode Island. That space is threaded by roads, asphalt lifelines of the population. When the magnitude 7.0 earthquake struck last week, some of the most visceral images showed roads that had broken apart. But within days, many of these same cracked highways had been smoothed back into ribbons of pavement by crews working around the clock.

The rapid response to damage in Anchorage shows how investing time and money into preparations for these kinds of large, infrastructure-hobbling events can pay off in the long-run, even when there’s no way to tell when or where disaster may strike.

“We have more quakes than any other state in the Union,” says Shannon McCarthy, a spokesperson with the Alaska Department of Transportation and Public Facilities. As a result, Alaska takes its earthquake preparation very seriously. The largest earthquake ever recorded in the country shook Anchorage to its core in 1964, causing a deadly tsunami and leaving in its wake damaged buildings, buckled roads, and a legacy that inspired years of earthquake preparation and policies. Strong building codes put in place post-1964 helped make the area more secure than other earthquake-prone areas, like Seattle.

The 50th anniversary of the 1964 quake took place just four years ago, and officials took the opportunity to update their earthquake plans, hold drills, and generally prepare for when a quake would hit in the future. “I think that really helped,” McCarthy said.

Over the past six months, a less ground-shaking development also helped prepare the teams on the ground for that moment. In March, a truck slammed into a bridge on the only major road connecting Anchorage to one of its suburbs, shutting down the throughway for days. In the months after the collision, the Department of Transportation went through and updated its recovery plans in the event of another damaging incident.

All that preparation readied Alaska residents to spring into action as soon as the shaking from the initial quake subsided. Bridge inspectors based in Alaska’s capital, Juneau, packed and got on a plane that night. Arriving before midnight, they immediately started checking on the 243 bridges that had been impacted by the shaking. After checking in on damaged homes and offices, government employees and contractors within the quake zone also got to work, readying themselves to do a job that wouldn’t be easy during this time of year.

Working 24/7, they cleared away the broken asphalt, saving it to be melted down at a later date. Then, crews with heavy equipment began digging out water-saturated sediments that slipped or sunk during the quake. They trucked in or gathered fresh material and compacted it, creating a sturdy earthwork base. Atop that, they placed large rocks, finer gravel, and finally, asphalt.

“Our asphalt plants were all shut down for the winter,” McCarthy says. Thick and tarry, asphalt needs to be heated up from a solid form before it can be spread out in a thick layer to make a road. But Alaska in late fall is bitterly cold, and frozen asphalt can take a week or longer to melt into a sticky, pliable material. Soon after the earthquake struck, owners of asphalt plants switched on their heaters. “We were fortunate that they did that.” McCarthy says. “By the time we’d finished the earthworks, the asphalt plants were ready to go.”

According to McCarthy, it was one of the first times that paving had ever occurred in winter. Snow was moving in to the area quickly, but the still-warm asphalt stayed clear just long enough for the crews to paint temporary lines on the roads. They couldn’t use the paint typically used on Alaska roads, an epoxy filled with glass beads and grit that prevents cars from skidding. It’s made to withstand the brutal wear and tear Alaskans put on their roads during the colder months, when layers of sand and tires wrapped in chains keep cars on the road, but would swiftly wear other paints down into oblivion. Unlike the asphalt, applying this paint has to wait for summer, when the weather is more amenable than it is now.

The crews worked through some days of heavy, wet snow, high winds of 65 miles per hour. And the weather wasn’t the only natural element being a pain — the ground shook with near constant aftershocks. In addition to inducing seasickness in several Alaskans, the shaking also carved crescent-shaped bites out of some of the roadways, or shook the ground so hard that the soil under the freshly paved roads settled, forcing a do-over.

Alaska DOT &PF

The earthquake hit on Friday morning at 8:29AM local time. By the next Wednesday at 4AM, all eight major transportation corridors that had been severely damaged by the quake had re-opened. Dozens of others are still awaiting repair, and officials are asking selfie-takers to stay away from their still-cracked surfaces, no matter how visually appealing they might be.

Similar situations play out in other places of the world, especially at bottlenecks where a web of roads narrows down to a precious few lanes. Japan can fix an intersection-eating sinkhole in less than a week. California, which has seen far more dramatic earthquake-induced road damage, has comparable plans in place.

As impressive as the completed sections are, this is still just a temporary fix. While most roads in Alaska have to be built to last for 20 years, these are only meant to carry people through the summer. When warmer weather returns, the asphalt plants will spark to burbling life again, and the crews will return to the same once-shattered spots to build more permanent roads.

Roads are important threads of human civilization around the world, but they are especially entwined in Alaskan life, where wilderness is only sparsely dotted with towns, and there are fewer detours available to re-direct traffic. “Alaska is different from many states in that in many cases we usually only have one road in and one road out. That’s true with Anchorage. We have one road to the north and one road to the south, so we’re particularly vulnerable if there is a break in the line,” McCarthy says.

In this case, breaks in the line were swiftly repaired, mirroring quake recovery in other areas of the city. Supply lines stayed intact, utilities were swiftly restored, damage was minimal, and, most importantly, there were no fatalities.

In some ways, the minimal damage and recovery offer a beacon of hope to communities facing down other natural hazards, whether that’s hurricanes, fires, floods, rising sea levels, or more earthquakes. Preparation makes a difference.

“In terms of a disaster, I think it says more about who we are than what we suffered,” Anchorage Mayor Ethan Berkowitz said Saturday at a press briefing, according to the AP. “People pulled together. We followed the plans that were in place. We looked after one another. And when people around the country and around the world look at this, they’re going to say, ‘We want to do things in the Anchorage way because Anchorage did this right,’” Berkowitz said.

https://www.theverge.com/2018/12/8/18128983/alaska-earthquake-roads-fixed-anchorage-damage