活动支座摩擦作用对连续梁桥固定支座剪力的影响

目前认为活动支座摩擦作用对连续梁固定支座剪力起有利的降低作用,抗震分析时一般忽略活动支座摩擦作用的影响。为了研究连续梁桥活动支座摩擦作用对固定支座剪力地震反应的影响,建立了考虑活动支座摩擦作用的连续梁桥抗震分析有限元模型,计算了各种情况下的固定支座剪力。研究发现,活动支座摩擦作用并不是在任何情况下都是有利的,根据分析结果给出了需要考虑活动支座摩擦力的情况,提出固定支座剪力简化计算公式需要综合考虑结构的自振特性及场地反应谱的影响。

Friction effect of movable support on fixed support shear force of continuous beam bridge

At present the friction action at movable support is generally considered favorable to the shear force at the fixed support of continuous beam bridge,and the friction action is neglected at most cases of seismic analysis.The seismic finite element model with friction element was established to study the effect of the friction action at movable support on the seismic response of the shear force at fixed support,and the shear forces of the fixed support under different conditions were calculated.The results indicate that the friction action of movable support is not favorable in any event,the cases that the friction action at the movable supports must be taken into account is put forward according to the results.The simplified formula for the shear force at fixed support should consider the effect of natural frequency of the bridge structure and ground spectrum.