通过6个缩尺为1∶5的高速铁路圆端形桥墩模型的低周反复加载试验,研究剪跨比、配筋率和配箍率等参数对桥墩抗震性能的影响规律.结果表明,在低周反复荷载和轴压荷载的共同作用下,低剪跨比和高剪跨比下高铁桥墩模型的破坏模式分别为弯剪型破坏和弯曲型破坏;随着配筋率、配箍率和剪跨比的提高,桥墩模型的位移延性和累积滞回耗能提高;试验测得剪跨比为2.5时桥墩模型的位移延性系数为4.66~4.93,仅能满足现行铁路工程抗震设计规范的最低要求;配筋率和配箍率对桥墩模型的刚度退化效应和残余位移影响较小.
Six round-ended pier models for high speed railway with the scale of 1 ∶ 5 were established.By means of low cyclic loading test,the influence laws of several important parameters on the seismic performance of pier were investigated,such as the shear span ratio,reinforcement ratio and stirrup ratio,etc.Results show that,with the combined action of low cyclic loading and axial compressive loading,the failure modes of high speed railway bridge pier models with low and high shear span ratios are shear-bending failure and bending failure respectively.With the increase of reinforcement ratio,stirrup ratio and shear span ratio,both the displacement ductility and accumulated hysteretic dissipated energy of pier models are increased.When the shear span ratio is 2.5,the displacement ductility of pier model measured by tests is in the range from 4.66 to 4.93,which can only meet the minimum demand in current seismic design code for railway engineering.In addition,it's found that both the reinforcement ratio and stirrup ratio have little influence on the stiffness degradation and residual displacement of pier model.