活动支座摩擦效应对墩底地震反应的影响OACSTPCD

Sliding bearings are widely used in non-fixed piers of long-span continuous beam bridges,cable-stayed bridges and suspension bridges.Piers of a long-span bridge with sliding bearings at pier top were selected as the research target to study the influence of frictional effect of sliding bearings on the seismic response at the bottom of non-fixed piers.The results show that for non-fixed piers with relatively small pier mass,the seismic response at pier bottom increases with the increase of friction coefficient.However,for non-fixed piers with relatively large pier mass,the seismic response at pier bottom first decreases and then increases with the increase of friction coefficient.Furthermore,this paper studies the mechanism behind the variation in seismic response at pier bottom,which initially decreases and then increases with the increase of friction coefficient.The results show that when the friction coefficient is small,the continued direction reversal of friction force of the support and inertial force of the pier under seismic loading may reduce the response at pier bottom with the increase of friction coefficient.Since the friction coefficient of actual bridge support depends on a wide range of factors,the seismic response at the pier bottom calculated under a given friction coefficient from codes can be smaller than the actual response,leading to increased post-earthquake repair time and cost or reduced safety of the structure.