Being inside a building during an earthquake is, at best, a little unsettling, but it’s extremely difficult to measure the movement of an entire building. Last year, researchers at MIT were able to use slow motion cameras to visualize how much a tower crane moved during normal conditions, which gave insight into the stress a crane undergoes. Measuring the effects of an earthquake is a little trickier, so the US Geological Survey (USGS) had to get a little creative to capture it.
USGS’ National Strong Motion Program is dedicated to recording the effects earthquakes have on our structures. They currently have sensors loaded in more than 660 ground sites and more than 180 buildings, bridges, dams, and other structural arrays. Most sites, for obvious reasons, are located in the Western US. Each building contains anywhere from 3 sensors (Desert Center, CA’s Hinds Pumping Plant) to 72 (Rincon Hill Tower in San Francisco and UCLA’s Factor Building in Los Angeles).
The Frontier Building is the subject of the video below. Built in 1982, the 219 feet (67m) tall building is the home to many State of Alaska offices in Anchorage. On January 24, 2016, the building was rocked by a 7.1 magnitude earthquake. Thanks to the USGS’ 36 sensors located in and around the building, we are able to see exactly how a building sways, twists, and shakes during a catastrophic event like this. To help visualize the event, the motions have been magnified by 300x their actual movement, so it looks a little more dramatic than it actually was. This research does, however, give designers key insight to real world conditions which could prove or disprove their calculations.
Video below was uploaded to Youtube by USGS.
Concrete is an extremely strong building material, but has a notoriously weak tensile strength. In order to resist tension, bending, and shear forces, steel rebar or other reinforcement materials are added either prior to the placement or into the mix. Even with reinforcement, concrete is still extremely rigid and prone to cracking. In the event of a major earthquake, the uneven and horizontal forces can cause structures to crack and, in the worst case, cause failure.
Construction Safety is talked about constantly. There are many construction companies that take it very seriously. There are also many that don’t. All will say it’s their top priority.
So what can a city do that’s facing regular worker deaths and increases in workplace injuries? New York City has decided to require extensive safety training for all of the 185,000 construction workers in the city.
According to the Workzonesafety.com, nearly half (46%) of all work zone-associated worker fatalities from 2003-2010 were caused by being struck by a vehicle. Surprisingly, only around 2% of those workers were killed by a drunk driver. From 2003 to 2015 (the last year this data was updated), a total of 1324 work zone fatalities have been recorded, which averages to about 102 per year.
Residents living near a Jersey City, New Jersey construction site were frightened as they watched “explosions” of smoke coming out of holes in the ground.
Portable toilets are the setting for many pranks around a construction site, but I never thought there could be something worse than just getting stuck in one. Turns out I was extremely wrong, because a worker in New Orleans was run over by a dump truck while using the port-a-john.
At last week’s National Safety Council Congress & Expo, OSHA’s deputy director of Directorare of Enforcement Programs, Patrick Kapust, announced their 10 most frequesntly cited safety violations for their fiscal year 2017, reports the National Safety Council.
As we saw after the Lake Oroville Dam in California collapsed earlier this year, dam failures can have sudden and devastating effects. Recent footage showing raging muddy waters swallowing a construction site in a matter of seconds has been shared after river dam in Thatom, Loas failed.
On Saturday, September 23, OSHA’s much talked about and controversial new Silica Dust Exposure Limit regulations went into effect. Late last week, the Acting Deputy Assistant Secretary of OSHA, Thomas Galassi, released a memorandum that issues a 30 day “grace period” for compliance.
[guest post] Working in construction certainly has its upsides - you get in a great workout, you learn valuable skills, and you develop incredible camaraderie on the jobsite. However, it also is one of the most dangerous jobs you can have.
Hurricane Irma ripped through the Caribbean and landed in South Florida a little over a week ago, sadly killing at least 50 people in Florida and causing plenty of property damage. High winds that accompanied the storm also caused the collapse of 3 construction cranes – two in Miami and one more in Fort Lauderdale. The crane in Fort Lauderdale was recently dismantled and the action was caught on video.