高墩大跨混凝土连续刚构桥梁抗震性数值分析

Numerical Analysis of Seismic Resistance of High Pier Large Span Concrete Continuous Rigid Frame Bridge

针对高墩大跨连续刚构桥在地震动作用下易出现更大振动,容易对桥梁固定墩结构造成严重破坏的问题。通过建立有限元模型来模拟不同阶态下的连续刚构桥振动特性,获得不同墩高以及不同地震波下高墩大跨混凝土刚构桥的抗震特性。研究结果表明:高墩高连续刚构桥主梁部分表现出横弯和竖弯振型,竖向最容易产生失稳现象;在EI Centro记录工况下,桥梁墩顶处产生的位移量明显小于边跨处位移,墩底截面积混凝土结构并未出现显著的压缩破坏,整个墩底截面处于弹性工作阶段;卧龙地震动下的截面钢纤维拉应变均超过了材料屈服应力下的应变量,截面钢筋已经完全进入了塑性变形阶段。

in view of the vibration of high pier and large span continuous rigid frame bridge,it is easy to have more vibration,and it is easy to cause serious damage to the fixed pier structure of the bridge.By establishing the finite element model to simulate the vibration characteristics of continuous rigid frame bridge under different order conditions,the seismic characteristics of high pier and large span concrete rigid frame bridge under different seismic waves are obtained.The results show that the main girders of high pier and high continuous rigid frame bridge have transverse bending and vertical bending mode,which is the most prone to instability.In el Centro record,under the condition of bridge pier top displacement produced by the obvious displacement is less than the side span,pier bottom section area of concrete structure is not significant compression failure,the end of the pier cross-section in the elastic work stage;Under the vibration of the wolong,the strain of the steel fiber is more than the dependent variable under the yield stress of the material,and the section steel bar is completely in the plastic deformation stage.