Investigation of Bearings Unseating of Cable-stayed Bridges under Earthquakes

Under strong earthquakes, bearings of cable-stayed bridges usually separate from the main beam. This paper adopts a cable-stayed bridge as the background project to study the influences of bearings unseating. Moreover, the effects of auxiliary piers on bearings unseating of cable-stayed bridges subject to earthquakes are also researched. Numerical results show that bearings unseating that may happen on transition pier and main tower result in large vertical displacement of main beam and bearings pressure. The position of auxiliary pier on the side span has an important influence on the bearings compressive force and girder vertical displacement of transition pier. Increase of bearings constant load pressure of auxiliary piers can reduce the vertical displacement of girder to some extent. However, the large bearings constant load pressure may causes large pounding force that should not be neglected in cable-stayed bridges design.