A more recent, and possibly the first, well-documented example of complete structural failure analysis resulted from the 1847 collapse of the Dee River railroad bridge in England. It was built using cast iron main girders between spans with wrought iron supports. After extra ballast had been applied to the track across the bridge as a precautionary measure against timber fires, one of the spans collapsed under a passing train causing injuries and fatalities.
The incident initiated a review process which is generally followed by forensic engineers to this day: an investigation was performed by a lead engineer who examined the site of the failure, collected materials, performed testing and analyses, reviewed witness statements, recreated events, and formulated a report attributing causation of the structural failure. And like modern investigations today, the failure analysis was not conclusive, but was able to determine probable cause. The design was deemed defective allowing fatigue failure of a cast iron beam, exacerbated from the weight of the extra ballast which had been applied only a few hours prior to the collapse. The wrought iron supports did not strengthen the structure as intended due their poor design implementation in the structure. Testing of the materials showed cast and wrought iron was prone to fatigue cracking failure, calling into question its use on other bridges and structures. Finally, continued failure of bridges and other structures using cast and wrought iron led to the development of high strength steels and other alternative materials.
View the original article here
This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.
0 comments:
Post a Comment