Introduction
The I-35W bridge was fully constructed and opened in November 1967 over the West Mississippi River in Minneapolis, Minnesota. According to Federal Highway Administration (FHWA), the length of the bridge was 1907 feet and its maximum span length was 458 feet. It had 8 traffic lanes and a height of 64 feet above the water. On the evening of August 1st, 2007 this steel arch deck truss bridge collapsed during rush hour. This paper will investigate the cause of this failure and provide some potential solution(s) to prevent similar failures.
What Happened
As reported by the New Building Material & Construction World (NBMCW), in the early afternoon, construction equipment and aggregates (sand and gravel for making concrete) were supplied …show more content…
As stated by the National Transportation Safety Board (NTSB), the main reason behind the failure of the bridge was the installation of the wrong gusset plate. Gusset plate are thick sheets of steel that are used to connect beams and girders to columns or to connect truss members. They not only serve as a method of joining steel members together, but they also strengthen the joint. The gusset plates were supposed to be one inch thick but half-inch thick gusset plates were installed. The extra weight of the construction equipment and materials, and traffic during rush hour led to the failure, which began at the weakest link of the truss where the half-inch gusset plates were installed. The structure and deck suddenly collapsed into the river, and into the river below. The south part topped 81 feet eastward in the process.
Why it wasn’t prevented?
The lack of proper maintenance and repair led to the collapse of the I-35W bridge. The I-35W bridge had been classified ‘structurally deficient’ since 1991 when the superstructure received its first condition rating of 4 (poor condition). In this case, ‘structurally deficient’ means there are elements of the bridge that needs to be monitored and/or repaired. It also implies the bridge must be inspected frequently and maintained. After inspections, however, the structural problems of the bridge were totally ignored and there were no steps taken to fix them.
Who Is Responsible for the
The I-35W bridge was fully constructed and opened in November 1967 over the West Mississippi River in Minneapolis, Minnesota. According to Federal Highway Administration (FHWA), the length of the bridge was 1907 feet and its maximum span length was 458 feet. It had 8 traffic lanes and a height of 64 feet above the water. On the evening of August 1st, 2007 this steel arch deck truss bridge collapsed during rush hour. This paper will investigate the cause of this failure and provide some potential solution(s) to prevent similar failures.
What Happened
As reported by the New Building Material & Construction World (NBMCW), in the early afternoon, construction equipment and aggregates (sand and gravel for making concrete) were supplied …show more content…
As stated by the National Transportation Safety Board (NTSB), the main reason behind the failure of the bridge was the installation of the wrong gusset plate. Gusset plate are thick sheets of steel that are used to connect beams and girders to columns or to connect truss members. They not only serve as a method of joining steel members together, but they also strengthen the joint. The gusset plates were supposed to be one inch thick but half-inch thick gusset plates were installed. The extra weight of the construction equipment and materials, and traffic during rush hour led to the failure, which began at the weakest link of the truss where the half-inch gusset plates were installed. The structure and deck suddenly collapsed into the river, and into the river below. The south part topped 81 feet eastward in the process.
Why it wasn’t prevented?
The lack of proper maintenance and repair led to the collapse of the I-35W bridge. The I-35W bridge had been classified ‘structurally deficient’ since 1991 when the superstructure received its first condition rating of 4 (poor condition). In this case, ‘structurally deficient’ means there are elements of the bridge that needs to be monitored and/or repaired. It also implies the bridge must be inspected frequently and maintained. After inspections, however, the structural problems of the bridge were totally ignored and there were no steps taken to fix them.
Who Is Responsible for the