What caused the I 35 bridge in Minnesota to collapse?

What caused the I 35 bridge in Minnesota to collapse?

The National Transportation Safety Board ultimately determined that the probable cause of the collapse of the I-35W bridge “was the inadequate load capacity, due to a design error . . . of the gusset plates at the U10 nodes, which failed under a combination of (1) substantial increases in the weight of the bridge.

What was the collapse of the Minneapolis I 35 bridge blamed on?

gusset plates
The National Transportation Safety Board blamed the collapse on gusset plates, which were half as thick as they should have been due to a flaw in the original design. The new bridge opened to the public on Sept. 18, 2008 and a memorial for the victims was also built near where the bridge once stood.

Which bridge collapsed in Minnesota?

I-35W bridge
On Aug. 1, 2007, Minnesota suffered a tragedy of historic proportions when the I-35W bridge (bridge 9340) over the Mississippi River in Minneapolis collapsed.

How did the Mississippi River bridge collapse?

The bridge opened in 1967 and was Minnesota’s third busiest, carrying 140,000 vehicles daily. The NTSB cited a design flaw as the likely cause of the collapse, noting that a too-thin gusset plate ripped along a line of rivets, and additional weight on the bridge at the time contributed to the catastrophic failure.

Who was responsible for the Minneapolis bridge collapse?

And the National Transportation Safety Board determined that it was a design flaw, and not deferred maintenance, neglect, or other problems, that caused the 35W bridge to collapse. Gusset plates that hold the bridge’s huge steel beams together were only half as thick as they should have been.

What year did the bridge collapse in Minneapolis Minnesota?

Remembering The I-35W Bridge Collapse 10 Years Later The I-35W bridge was one of Minnesota’s busiest, carrying 140,000 cars a day over the Mississippi River. It collapsed during rush hour on Aug. 1, 2007. Ten years later, the disaster still looms large.

Why was prestressed concrete used for bridge construction?

The use of Prestressed Concrete for construction of bridge, wharf and other civil structures expanded rapidly from the 1960’s onwards, due mainly to the increased spans and economy that it provided.

What causes cracks at the end of precast concrete beams?

One of the primary concerns of the use of precast prestressed concrete beam (PPCB) bridges is cracking and spalling of the concrete towards the ends of the beams due to contamination from water and deicing chemicals, which results in exposure and corrosion of the beams’ reinforcement and prestressing strands.

Where is the post tensioned slab bridge in Winona MN?

Figure 3 – This is a detail from the original 1957 engineering plan for the post-tensioned slab design for Bridge 9065, originally located on Highway 61 just south of Winona, but now replaced.

Can a damaged strand of prestressed concrete be repaired?

Damaged strand cannot be repaired and is commonly cut out, with supplementary strengthening methods including carbon fibre utilized to compensate for the lost strength. Conventional Patch Repairs cannot be used due to the in-built compression forces in the concrete and the likelihood of damage to the brittle, prestressed strands.

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