摘要
为研究活动支座的不同状态对桥梁结构弹塑性地震反应的影响,根据地震中活动支座的3种不同状态分析了其对应的有限单元模型;利用间隙单元和钩单元的组合构造了活动范围受限情况下的活动支座有限单元模型;采用活动支座的3种单元模型,考虑不同配筋率情况下的桥墩非线性建立了连续梁桥的3种全桥有限元模型,进行了非线性时程反应分析。结果表明,在活动支座活动范围受限甚至失去滑动能力的情况下,活动支座墩承担的地震作用增大,尤其在配筋率较低的情况下其墩底最大曲率达到甚至超出了固定支座墩的曲率,地震中活动支座墩也有可能发生破坏。在桥梁抗震设计中应根据支座的工作状态精确模拟其作用,并考虑其可能产生的破坏对活动支座墩产生的不利影响。
To study the effect of different working states of movable support on elasto-plastic seismic response of bridge structure,the corresponding finite element models of 3 working states of movable support are analysed. The finite element model of movable support with limited moving range is established by a combination of gap element and hook element. Based on the 3 models of movable support,3 finite element models of the whole continuous girder bridge considering the nonlinearity of piers with different reinforcement ratios are established,and the nonlinear time-history response analysis is performed. The result indicates that the seismic action suffered by movable support pier increased when the moving range of the movable support is limited or lost its sliding ability,the maximum curvature at the bottom of pier may achieve even beyond that of the fixed pier especially in low reinforcement ratio,and the movable support pier may be destroyed. The effect of the movable support should be accurately simulated according to its working state in seismic design,and the adverse effect of damage of movable support on the pier should be taken into account.
引文
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