特征参数对高速铁路桥墩抗剪性能的影响研究

Study on influence of characteristic parameters on shear performance of high-speed railway bridge piers

为了研究特征参数对高铁桥墩抗剪性能的影响特征及规律,以PEER数据库中墩柱为原型,基于OpenSEES平台分别建立了考虑弯剪耦合效应和弹性剪切效应的精细化墩柱模型.经对比验证发现:对于可能发生脆性破坏的墩柱,墩柱的弯剪耦合效应对模拟结果有决定性影响.以京沪高铁某连续梁桥桥墩为对象,建立考虑弯剪耦合效应的精细化分析模型,分析了特征参数对高铁桥墩抗剪性能的影响,结果表明:纵筋率对高铁桥墩抗剪承载力的影响最大,剪跨比次之,轴压比的影响最小;纵筋率的增大使桥墩抗剪承载力最大增加了292%,延性水平降低;随着轴压比的提高,桥墩抗剪承载力有所增大,最高增幅为50%;增大剪跨比可显著提高桥墩延性,但会使抗剪承载力显著降低.

In order to study the influence of above parameters on shear performance of high-speed railway bridge piers,using piers in PEER database as prototype,refined numerical models considering the nonlinear and elastic shear effect were constructed based on the OpenSEES platform respectively.Then the results were compared and verified,which shows that the flexure-shear interaction effect has a crucial influence on the shear performance of piers that suffer brittle failure.Taking the pier of a continuous beam bridge of Beijing-Shanghai high-speed railway as object,the shear performance of piers with multiple parameter levels were studied.The results show that,the reinforcement ratio has the largest influence on the shear resistance while the shear span ratio are the secondary factor of shear capacity,and the axial load ratio has the smallest influence.The increasing of reinforcement ratio leads to a maximum shear capacity increment of 292%and a ductile decrement.With the increasing axial load ratio,the maximum increment of shear capacity is 50%.With the shear span ratio increases,the ductile of bridge pier increase apparently while shear capacity decrease.