考虑混凝土损伤的隔震连续梁桥碰撞响应分析

针对隔震连续梁桥纵桥向主梁与桥台碰撞问题，以一联三跨混凝土隔震连续梁桥作为算例，采用ABAQUS建立了考虑混凝土材料损伤及三维接触碰撞的有限元模型。在此基础上，应用显式积分算法分析了纵桥向地震作用下隔震连续梁桥的碰撞响应，探究了伸缩缝间隙以及支座屈服位移对碰撞响应的影响。研究结果表明:采用三维有限元模型计算得到的碰撞持时与应力波理论得到的结果吻合较好；随着碰撞的发生，混凝土材料损伤积累，碰撞持时有增加的趋势。增大伸缩缝间隙将减小碰撞次数的发生，但对最大碰撞力的影响趋势不明显；随着支座屈服位移的增加，碰撞次数显著减小，但最大碰撞力变化不大。

ANALYSIS ON POUNDING RESPONSE OF ISOLATED CONTINUOUS GIRDER BRIDGE CONSIDERING CONCRETE DAMAGE

In order to cope with the pounding problem between the girder and the abutment of isolated continuous girder bridges, finite element code ABAQUS is used to build a computational model which includes the concrete damage plasticity (CDP) and the spatial arbitrary pounding, with a three-span concrete isolated continuous girder bridge taken as an example. Based on this model, a dynamic explicit integration algorithm is utilized to calculate the pounding effect under longitudinal seismic input, and to investigate the influences of the expansion joint and yielding displacement of bearing on pounding response. The analytical results show that the pounding duration derived from this spatial arbitrary pounding model can tally agree with that from wave propagation theory. Pounding duration tends to increase when more poundings damage the concrete material of the main girder. The enlargement of expansion joint will reduce the number of pounding, but has little correlation with the maximum pounding force. The yielding displacement of isolated bearing increases while the number of pounding significantly reduces, the maximum pounding force, nevertheless, shows few changes.