Bridge Bearing Performance in Ontario
D. Manning and K. Bassi
Appears on pages(s):
acceptability; bridge bearings; installing; manufacturing; performance; reviews; structural design; Design
The historical development of using bearings in Ontario and the current design requirements contained in the Ontario Highway Bridge Design Code and the Ministry's bearing specifications are reviewed. Numerous instances of unsatisfactory bearing performance, especially of proprietary rotational and sliding bearings, are described. Examples are given of unsatisfactory performance resulting from poor bridge design practices, improper bearing design, poor manufacturing procedures, and incorrect installation. In all cases, the action that has been taken to prevent a recurrence of the deficient performance is presented. The basic philosophy in design is to use the minimum number of bearings consistent with the articulation of the structure. The severity of the service environment has been recognized with the result that a high degree of corrosion protection is specified and a provision made for bearing replacement. All bearings are required to have a capacity for rotation about all three axes, which means that rockers, rollers, sliding plates, and cylindrical bearings are no longer used. The paper also describes the contractual relationships involved in the supply of highway bridge bearings and concludes that while a performance specification and guarantee would be desirable, such an approach is not practical.