Posted on April 18, 2018 in General
It was supposed to be at the forefront of bridge-building technology – a glimpse into the future of bridge construction in the United States.
What had begun as the centerpiece of urban development ended with six people dead and ten injured. Builders and designers intended the Florida International University (FIU) Sweetwater University City Bridge to connect the students of (FIU) with the adjacent community, but its surprising collapse was devastating.
On April 15, the 174-foot UniversityCity Pedestrian Bridge under construction near an entrance of FIU in Miami gave way and fell onto a roadway beneath it, trapping vehicles. The National Transportation Safety Board has yet to determine the reason for its collapse. Some experts suggest some reasons for the failure, including its design.
The Design of the Bridge
Builders created the bridge using a relatively new building technique. It utilized prefabricated materials called accelerated bridge construction, simplified as ABC. Builders constructed parts of the bridge away from the final location for the least amount of traffic blockage or other various construction nuances. In fact, part of the conditions of constructing the bridge meant it could not block traffic flow.
While it may seem like a non-secure way to construct bridges, the UniversityCity Pedestrian Bridge isn’t the first of its kind and won’t be the last. Builders have constructed over 1,000 bridges in the U.S. using the ABC technique that citizens use today.
Many believed the UniversalCity Pedestrian Bridge to be a cable-stay design when news first broke of the incident. Cable-stay bridges appear similar to suspension bridges but are more stiff and durable. However, the UniversalCity Pedestrian Bridge was a truss design – a modern take on an older bridge construction method.
The Miami Herald claims that truss designs are a type of construction style that’s prone to failure. The truss design included cables for aesthetic appeal. Cable bridges have become increasingly popular in Florida and around the nation.
Why the Design Failed
Aside from being an ABC pedestrian bridge design, which can easily lead to problems, evidence suggests a few potential reasons worked in concert to cause the collapse:
- Reported cracks. Days before the incident, crews reported cracking in concrete on the north end of the structure. A report by the Florida Department of Transportation suggests the engineer for the FIGG Bridge Group stated the cracking wasn’t unsafe, however.
- A support truss failed. Growing evidence suggests a diagonal support truss failed at one end of the bridge. This caused the bridge to buckle under itself and fall onto Southwest Eighth Street.
- Over tightening of the rods. Bridge subcontractor crews were tightening steel rods inside of a support truss on the north end of the structure when the bridge collapsed. The crew was working in the same general area as the cracks reported days earlier.
- A damaged structural piece. Some experts point to a structural piece that incurred damage when builders put the bridge together as part of the ABC design. This didn’t lead to an immediate collapse, of course, since the accident didn’t occur until five days later.
- The designer and builder did not have perfect records. Designers contracted Miami-based Munilla Construction Management to build the bridge alongside FIGG Bridge Engineers. In 2012, FIGG received a hefty fine for a bridge collapse in Virginia. Some accused Munilla of imperfect work when a temporary bridge at Fort Lauderdale International Airport collapsed.
While fatal bridge collapses are relatively rare occurrences, future bridge construction designers and builders should take heed of the things that went wrong with the UniversalCity Bridge.
As a citizen, you should expect safety when you are crossing on a bridge or driving under a bridge. Talk to one of our Florida personal injury lawyers if you have questions after a construction injury.