Building techniques have significantly changed in the last 90 years. When designing a new structure or making upgrades to existing ones, architects and engineers prepare for them to be impacted by earthquakes.
“Most of Montana is seismically active. Although, you know, luckily we don’t get a lot of large earthquakes, we have to plan for the worst,” said architect Mark Ophus with SMA Architecture + Design.
(WATCH: How modern engineering improves building durability in earthquakes)
How modern engineering improves building durability in earthquakes
One of the big factors why there was so much damage in 1935, though the quakes weren’t terribly large, was the type of material and techniques used in construction. Many of the buildings were unreinforced brick, which shook apart during the quakes.
There are a couple of factors as to why brick and other stone masonry were commonly used a century ago in Helena. The Queen City of the Rockies experienced several devastating fires in its early years. Shipping steel was also costly, and bricks could be made right in Helena.
HELENAHISTORY.ORG
Houses damaged by the 1935 earthquake
CLICK HERE TO LEARN MORE ABOUT THE BIG SHAKE OF 1935
It’s hard to plan for a big earthquake, and it often takes an event like 1935 to drive changes and innovation.
“Every time there’s a new earthquake and a lot of damage occurs, we engineers go in and assess what worked and what didn’t work,” explained structural engineer Travis Bradshaw with DCI Engineers.
Although hundreds of buildings were destroyed during the big shake, many survived and could be repaired. But as the years go on, upgrades often need to be made.
Central School in downtown Helena is a more recent example of when a building had to be replaced or repaired due to seismic concerns. The previous building had to be evacuated after a study confirmed that it was at risk for catastrophic failure should a significant earthquake occur.
MTN News
Old Central School in Helena
SMA designed the new building after the decision was made to replace the school.
“When we got involved and watched the demolition of that building, it came down so much faster than I think anybody anticipated,” recalled Ophus. “There was an excavator that was being used to pull it down, and it had to quickly, go in reverse to escape the wall falling down upon it
Modern buildings use more steel and reinforced materials than in the past, which do better in a quake.
Damage from a major quake is likely unavoidable, but builders take steps to protect any occupants as best as they can. Reinforcing stairwells and making sure overhanging material won’t come down on people are factored into designs.
“I have two kids in the school district here in Helena, and it really makes, you know, makes me happy knowing that they’re going to go into a school or go into a structure that I know could withstand a seismic event or can withstand any loads that the environment throws at it,” noted Bradshaw.
