拉索式连梁装置设计参数对简支梁桥抗震效果的影响

Parametric design of unseating prevention devices for simply-supported girder bridge

连梁装置是一种有效的防止桥梁在地震中落梁的措施.基于一座常见结构形式的简支梁桥进行了不同设计参数的拉索式连梁装置的非线性时程分析计算,文章结合已有的国内外连梁装置设计方法,研究不同设计长度和初始间隙等参数对连梁装置限位效果及内力的影响.结果表明:连梁装置的限位效果随着初始间隙的增大逐渐减小,当初始间隙大于设计位移量时,连梁装置不再发挥作用;拉索长度对限位效果影响不大,但长度较小的连梁装置会导致内力增大,使桥墩墩底的弯矩增大及损伤程度加剧.

Unseating prevention device is an effective measure to prevent the bridge beam falling when bridge is hit by earthquake. In this paper, based on the existing domestic and foreign unseating prevention devices design method, the time-history analysis has been carried on a common structure in simply-supported girder bridge with different design parameters of unseating prevention devices, studying different design cable length and initial gap and other parameters of unseating prevention devices that limit the displacement and the internal forces effect. The results show that unseating prevention device limit effect gradually decreases with increasing initial gap, when the initial gap is greater than the amount of design displacement, unseating prevention devices work no longer; cable length affects the limiting of the displacement less, but smaller length of unseating prevention de- vices will result in increasing internal force and the bending moment at the end of pier and its injury severity.