The Mianus River Bridge is the range that carries Interstate 95 on the Mianus River in Cos Cob section in Greenwich, Connecticut. This is the second bridge on this site. The original bridge collapsed in 1983, killing three riders. The replacement range is officially named Michael L. Morano Bridge , after a state senator representing Greenwich.
Video Mianus River Bridge
Collapse
The bridge has a 100-foot (30.5 m) section of its deck that collapsed to the north on June 28, 1983. Three people were killed when two cars and two tractor-trailers crashed with a bridge to the Mianus River 70 feet (21.3 km). m) below; three people were seriously injured.
The death toll from the collapse is only a little because the disaster occurred at 1:30 am, when traffic was low on the often crowded highway.
Cause
The collapse was caused by a two pin failure and a hanger assembly that held the deck in place on the outer side of the bridge, according to an investigation by the National Transportation Safety Agency. Rust is formed on the pin bearings, exerting power on a hanger that is beyond the design boundary for the retaining clamp. This forces the hanging on the inside of the expansion joints in the southeast corner of the tip of the pin that holds it, and the load is moved to the outside hanger. The extra load on the remaining hangers starts to crack fatigue at a sharp angle on the pin. When it fails simultaneously, the deck is supported in only three corners. When two large trucks and a car enter the passage, the remaining expansion joints fail, and the deck falls into the river below.
Subsequent investigations mentioned the corrosion of the buildup of water due to inadequate drainage as the cause. During road repairs some 10 years earlier, the highway drain was deliberately blocked and the crew failed to unblock them when the road works were completed. The rain water leaked through the pin pads, causing them to rust. Outside bearings are critical and non-exaggerated fractures, design defects of this particular type of structure. The pads are difficult to inspect up close, although rust marks can be seen near the affected cushion.
The incident was also blamed on inadequate inspection resources in Connecticut state. At the time of the disaster, the state had only 12 engineers, who worked in pairs, assigned to inspect 3,425 bridges. The collapse occurred despite the national inspection procedure brought about by the collapse of the Silver Bridge in West Virginia in December 1967.
Reactions
I-95 traffic to the north was diverted to US-1 roads and local roads in Greenwich for 6 months, causing the worst traffic trouble the city had ever experienced. Only when a temporary truss carrying two lanes of northern traffic opened in November 1983 the traffic can be recovered. In 1984, the state began to make collective efforts to finance a replacement bridge.
In 1986, a $ 150 million bridge replacement project began. The new northern range opened in January 1989, allowing temporary north truss to be taken out of service and destroyed. In the former site, a new southern range was built. The southern range opened in November 1992, after the rest of the original bridge was taken out of service and destroyed. The replacement bridge completed in 1992 is a continuous girder design and floor beam, which eliminates the need for pin and hanger assemblies involved in the collapse of the original 1958 range. The associated cosmetic work and coastal recovery under the bridge continued to affect the area until early 1993. The new bridge, like the old one, contains six traffic lanes, but also contains an outer shoulder, features that do not exist from older and fewer narrow bridges.
After the replacement of the Mianus River Bridge, governor William O'Neill proposed a $ 5.5 billion transportation spending package to pay for the rehabilitation and replacement of bridges and other transportation projects in Connecticut.
Maps Mianus River Bridge
See also
- Bridge portal
- Connecticut Portal
- List of bridge failures
References
External links
- NTSB reports the collapse
- History of Connecticut Turnpike (I-95)
- "1983: Mianus River Bridge Collapsed". WTNH News8 (YouTube). June 28, 2013. Ã, - Archive news recording of disaster.
- June 28, 1983 on the Connecticut History website
Source of the article : Wikipedia
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