Steve Freihon/Related-Oxford
New York, New York
I-35W Bridge Collapse
We investigated the cause of the 2007 collapse of the 1,900-foot-long Interstate Highway 35 West bridge over the Mississippi River.
Lead Contact
Project Details
Project Partners
Robins, Kaplan, Miller & Ciresi L.L.P.
Location
Minneapolis, Minnesota
Completion Date
Overview
During the evening rush hour on August 1, 2007, a 1,900-foot section of Interstate Highway 35 West bridge between Minneapolis and Saint Paul, Minn., collapsed into the Mississippi River, killing 13 people and injuring 145. We conducted a study to determine the cause of the collapse on behalf of a consortium of 20 Minnesota law firms representing, pro bono, more than 90 victims and their families.
Highlights
- Our investigation included on-site observations, review of more than 50,000 documents, and detailed analysis of the entire bridge.
- Studies by the advanced analytics team included assessing the impact of fatigue, temperature and load redistributions on critical bridge members subjected to static and dynamic loads. A key component of the work was the construction of a forensic information model, an interactive, computer graphic model of the bridge that enabled engineers to catalog and access available information on each bridge component.
- Our findings pointed to failure of bearings to allow the normal movement of the bridge associated with thermal expansion. The resulting build-up of stress led to the collapse.
- Our analysis was completed by the one-year anniversary of the event, when the National Transportation Safety Board had to report its findings.
Our Team
Project News
Insight
Forensic Investigation Modeling: A New Forensic ToolJanuary 01, 2013
The investigation into the causes of the collapse in Minneapolis in August 2007 of the I-35W bridge required sifting through a vast amount of design, retroft, and maintenance data prior to initiating the complicated work of analyzing the condition and loading of the bridge at the time of collapse. A new forensic tool—forensic information modeling—was created to store all of these data, as well as the geometry, as a three-dimensional visual database, enabling the engineers to pinpoint possible trouble areas in need of further inquiry.
Insight
Analytical Approaches for Investigating the Cause of the I-35 West Bridge FailureApril 16, 2013
The I-35 West Bridge in Minneapolis Minnesota collapsed on August 1st, 2007 at 6:04 pm killing 13 people and injuring many more. A nearby security camera captured a video of the collapse. In order to determine the cause of the collapse, a set of analysis results using finite element models and hand calculations were combined into one non-linear model to simulate what occurred on the day of collapse. The collapse model contains the non-linear material properties, loading scenario and findings from the inspection history of the bridge.