Abstract:

Considering the economy of the damper and the replaceability after the earthquake， the friction damper with replaceable rubber in steel pipe （SPRFD） composed of high-strength bolts， steel pipe， movable baffles， fixed baffles， steel tie rods， and replaceable rubbers was proposed， and its basic structure and working principle were introduced. Through reciprocating loading test， the change rule of the hysteresis curve of the damper under different preloads were investigated， the change rule of the hysteresis response characteristics， equivalent stiffness and equivalent damping ratios under different loading displacements were analyzed， and the friction damage characteristic of the replaceable rubber was obtained. The seismic performance of railway self-centering bridge pier equipped with SPRFD was investigated through cyclic loading analyses. The results showed that the hysteresis performance of the damper was stable under the smaller preload， and the hysteresis loop had the characteristics of rigid-plastic model； As the preload increasing， the reciprocating cycle and large displacement loading decreased the damping force causing by rubber damage， and the hysteresis loop had the characteristics of elastic-plastic model. During the whole loading process， the dampers had a relatively stable equivalent viscous damping ratio. SPRFD with different preload had different effects on the hysteresis curve of the self-centering bridge piers. The value of the preload affected the unloading stiffness of hysteresis curve. The hysteresis curve had an obvious pinching under the larger preload. The larger preload helped the self-centering bridge pier enhance lateral strength.

Key words: bridge and tunnel engineering, friction damper, hysteresis behavior, self-centering bridge pier, seismic performance