Development of Steel Box Girders
The box girder bridge was a popular choice during the roadbuilding expansion of the 1960s and many new bridge projects were in progress simultaneously. A serious blow to this use was a sequence of three serious disasters, when new bridges collapsed in 1970 (West Gate Bridge and Cleddau Bridge) and 1971 (Koblenz Bridge). Fifty-one people were killed in these failures, leading in the UK to the formation of the Merrison Committee and considerable investment in new research into steel box girder behaviour.
Most of the bridges still under construction at this time were delayed for investigation of the basic design principle. Some were abandoned and rebuilt as a different form of bridge altogether. Most of those that remained as box girder bridges, such as Erskine Bridge (illus.), were either redesigned, or had additional stiffening added later. Some bridges were strengthened a few years after opening and then further strengthened years later, although this was often due to increased traffic load as much as better design standards. The Irwell Valley bridge of 1970 was strengthened in 1970 and again in 2000.
Read more about this topic: Box Girder Bridge
Famous quotes containing the words development of, development, steel and/or box:
“This was the Eastham famous of late years for its camp- meetings, held in a grove near by, to which thousands flock from all parts of the Bay. We conjectured that the reason for the perhaps unusual, if not unhealthful development of the religious sentiment here, was the fact that a large portion of the population are women whose husbands and sons are either abroad on the sea, or else drowned, and there is nobody but they and the ministers left behind.”
—Henry David Thoreau (1817–1862)
“The young women, what can they not learn, what can they not achieve, with Columbia University annex thrown open to them? In this great outlook for women’s broader intellectual development I see the great sunburst of the future.”
—M. E. W. Sherwood (1826–1903)
“The finest workers in stone are not copper or steel tools, but the gentle touches of air and water working at their leisure with a liberal allowance of time.”
—Henry David Thoreau (1817–1862)
“You’re the most beautiful woman I’ve ever painted. Not because you’re beautiful but because I’m in love with you. Hopelessly in love with you.”
—Muriel Box (b. 1905)