Rockman's Ramblings

Personal Reflections on I-35 Bridge Collapse in Minneapolis

On January 15, the National Transportation Safety Board released a safety recommendation letter report to the FHWA related to the I-35W bridge collapse in Minneapolis Minnesota that claimed the lives of 13 people and injured 145. The safety recommendations are based on the findings of an interim report from the FHWA Turner-Fairbank Highway Research Center  that some gusset plates, components of the steel trusses, were undersized (not thick enough). This deficiency was confirmed to be a flaw in the design and not construction-related based on review of the original drawings from the 1960s and inspection of the wreckage. Whether this was a calculation error or a drafting error will perhaps never be known as only portions of the original design calculations were located. But the point is that it was never caught by any reviewers.

When this event first happened back on August 1, I remember being very shaken up by it. After my initial sadness for the victims of the accident, my first thought as a geotechnical engineer was: “were the foundations at fault.” As more information came out, it quickly became evident that the failure did not have anything to do with the foundations but that it was related to the superstructure of the bridge. But this still was something that profoundly affected me. (Continues…)



City of Vancouver sues over failed shoring

The City of Vancouver is suing a developer, excavation contractor and their consulting engineer for the costs of repairs, overtime for city employees and lost revenue from parking meters etc stemming from an apparent failure of a shoring system that formed a 30-meter sinkhole. No mention of the developer’s name or the engineer, but the contractor was Matcon Excavation and Shoring. The site will be the future home of high-rise condominiums…if the City lifts it’s stop work order.

The failure of the shoring caused a break inf a 20-cm water main ultimately flooding the site. It also necessitated the closure of the adjacent street. Of course this invites the whole chicken or the egg scenario. The defendants will probably argue that the water line failed first causing the failure of the shoring, but of course the City Engineer, Tom Timm was not shy about fingering the shoring as being deficient.

"It’s some kind of a failure of the shoring system . . . either a design issue or the way it was put in place."



No Picture
Press Releases

Lawmakers Step Up To Address Dangerous Dams

House Approves 200 Million Dollar Authorization to Fix or Remove Ticking Time Bombs

Contacts: Garrett Russo, American Rivers, (202) 423-9494; Laura Wildman, P.E.; American Rivers, (860) 913-3960

Washington, D.C.— Millions of Americans are living in the shadow of dangerous dams all across the country, but that may be about to change, thanks to quick action by the House of Representatives to pass the Dam Rehabilitation and Repair Act of 2007 (H.R 3224), sponsored by Representative John T. Salazar (D-CO). The bill, which authorizes 200 million dollars to help fix, or remove publicly owned dams all across the country, now heads to the Senate.



Iraq Dam in Danger of Collapse

The Mosul Dam in Iraq is in danger of an "imminent collapse" according to a Washington Post article.  The dam threatens the lives of as many as 500,000 people in Mosul which could be innundated by over 60-ft of water if the dam fails. Parts of Baghdad could see as much as 15-ft of water. Read on for more info.