Bridge Failures - Failure Case Studies in Civil Engineering - page 56

FALLS VIEW BRIDGE
(1938)
On January 27, 1938, the Falls View arch bridge, downstream of Niagara Falls, was
torn from its foundation as a result of a severe ice jam. The bridge was a tourist
attraction, known as the Honeymoon Bridge.
The construction of the bridge started in 1895 and was completed in 1898.
The structure was a two-ribbed steel arch of 256 m (840 ft) span. Each rib was a two-
hinged truss arch with a uniform depth of 7.9 m (26 ft) and a rise of 45.7 m (150 ft).
The chord members were plate and angle box sections. Most of the other members
were steel sections with lattice connections. The original wooden deck of 14 m (46 ft)
width carried a two-track street railway and was supported by unbraced single
spandrels. The four concrete and stone foundations rested in solid rock approximately
12 m (40 ft) above the normal water level.
The ice jam was formed during the night of January 25, 1938. By the
following afternoon, ice had piled up to a height of 15 m (50 ft) above normal river
level, or 3 m (10 ft) above the pins supporting the arch. The ice pack moved down-
stream like a glacier for about 122 m (400 ft) covering at least 9 m (30 ft) of the
upstream truss, causing the failure of many of the bracing members. Shortly
thereafter the structure was closed to traffic. The movement of the ice pack was
halted, but the upstream truss continued to move very slowly downstream
accompanied by further buckling and failure of secondary members. On the afternoon
of January 27, the buckled section of the lower chord broke with loud report and the
bridge collapsed. The bridge was replaced by the Rainbow Arch, a fixed arch rib of
290 m (950 ft) span.
Lessons Learned
The principal cause of the failure was the proximity of the ice mass to the structure
and the flexibility of the structure. Although it is not always possible to design for
unusual natural phenomena, the foundation of bridges should be protected where
possible.
References
Buck, R.S. (1938). "Niagara Arch Memories," Engineering News Record , 120,
February 24, 297-298.
ENR.(1938). "Cable and Deck Salvaged from Falls View Bridge," Engineering News
Record , 120, February 24, 311.
ENR.(1938). "Falls View Bridge Sinks in River," Engineering News Record , 120,
559.
ENR.(1938). “Ice Power,” Engineering News Record , 120, 171.
ENR.(1938). "Record Ice Jam at Niagara Falls Wrecks Famous Arch Bridge,"
Engineering News Record , 120, February 3, 161,168-169.