1.School of civil Transportation Engineering,Hebei University of Technology;2.Hebei University of Technology;3.The Department of Transportation Highway Research Institute
National Key R&D Program of China(2017YFE0103000);Technology Development Program of Tianjin Transportation (2018-35);Science and Technology Program of Transportation Department of Hebei (TH-201916)
The aging and eccentric compression of plate rubber bearings are very important for the seismic safety of bridges.The elastic modulus of plate rubber bearing was measured by indoor aging test. According to the degree of aging and eccentric compression. The quasi-static test is divided into 16 cases, and the seismic performance indexes and change rules of the bearings under thermal aging, eccentric pressure and coupling are compared and analyzed .The results show that the hysteresis curve of the bearings under eccentric compression is relatively narrow. The area and equivalent damping ratio of the hysteresis curve decrease, and the horizontal equivalent stiffness of bearing increases. After aging, the shear deformation of the bearings decreases, the hysteresis curve is fuller with the increase of slip ratio for the given displacement amplitude,and the corresponding equivalent damping ratio increases.Under the condition of aging and eccentric compression, the slope of hysteresis curve is more gentle, and the energy dissipation capacity of bearing is obviously weakened.It is found that the common plate rubber bearing has the risk of falling off due to the excessive unidirectional accumulative slip in earthquake.It is suggested that in bridge maintenance, a limit device should be set on the underside of the bearing and timely adjust the bearing with severe eccentric compression.