板式橡胶支座与RC桥墩串联结构抗震性能试验研究

Experimental Study on Seismic Performance of Series Structure with Plate Rubber Bearing and RC Bridge Piers

为了探究非减隔震钢筋混凝土梁桥的典型震损模式,建立了相应的抗震损伤失效临界判别标准。针对服役桥梁结构局部缺损影响下其震损演变规律和震损模式不明确的问题,基于支座与桥墩串联结构力学理论计算模型,从抗震易损构件着手,设计并制作了4组典型普通橡胶支座和钢筋混凝土桥墩局部串联结构模型构件,并对此开展了水平单向拟静力试验研究,主要考虑了界面接触条件、支座抗剪刚度的影响。对不同参数影响下试验模型的损伤破坏特征、水平力-位移滞回曲线、耗能等抗震性能指标进行了对比分析。结果表明:支座抗剪刚度和串联结构界面接触条件可影响或改变局部串联结构的抗震损伤失效模式。其中,采用和未采用四氟滑板支座的串联结构典型损伤失效模式分别对应支座水平滑动位移较大、支座剪切变形大和下部墩柱损伤模式;支座与相邻结构的界面摩擦连接较弱或界面摩擦滑移,该类串联体系的水平位移-水平力滞回曲线较饱满,且显著降低下部墩柱的侧向位移,而支座和上部刚体侧移较大,实际工程中易发生碰撞和落梁震损模式,与延性抗震设计理念内涵存在差异。

In order to investigate the typical failure mode of non-isolated RC girder bridge under earthquake load,the corresponding critical criteria for seismic failure is established.Aiming at the problem that the unclear evolution rule and the type of seismic damage of the service bridge under the influence of local defects,on the basis of theoretical calculation model of the series structure with the support and the piers,starting from the seismic vulnerable components,4 groups of typical local series structural model members of ordinary rubber bearing and reinforced concrete pier are designed and manufactured,and the horizontal one-way quasi-static test is carried out.The influence of interface contact condition and bearing shear stiffness are mainly considered.The damage failure characteristics,hysteresis curves of horizontal force vs.displacement,energy consumption and other seismic performance indicators are comparatively analyzed.The result shows that(1) The contact condition of shear stiffness of the support and the interface of the series structure can affect or change the seismic damage failure modes of local series structure.Among them,the typical damage failure modes of the series structures with and without Teflon sliding plate support correspond to the large bearing horizontal sliding displacement mode and the large bearing shear deformation with damage of the lower pier column respectively.(2) For the series system with weak interface friction connection or interface friction sliding between bearing and adjacent structure,the hysteresis curve of horizontal displacement vs.horizontal force is fuller,and the lateral displacement of the lower pier column is significantly reduced.However,the lateral shifts of the support and the upper rigid body are large,and the seismic damage mode of collision and falling beam is easy to occur in the actual project,which is different from the connotation of the concept of ductility seismic design.