塔-梁纵向连接方式对多塔自锚式悬索桥抗震性能的影响规律

以福州市某在建的三塔自锚式悬索桥为工程背景,建立三维有限元模型,应用直接积分法进行非线性时程分析,分别研究纵向漂浮体系和约束体系下三塔自锚式悬索桥的抗震性能.计算结果表明:相对纵向漂浮体系而言,纵向约束体系中塔梁纵向约束可以有效地限制主梁的纵向振动,使得索鞍抗滑安全系数较大,边塔及中塔地震变形较小,主梁截面弯矩较小,梁端伸缩缝位移需求也较小.因此,从多塔自锚式悬索桥的抗震安全性角度考虑,建议采用塔-梁纵向约束体系.

The influence law of longitudinal constraints between tower and girder on seismic performance of self-anchored suspension bridge with multi-tower

Based on a practical project of self-anchored suspension bridge with three-tower located on Fuzhou city, the finite element model was established and direct integration method was used for nonlinear time history analysis. The seismic performance of longitudinal floating system and longitudinal constraint system were discussed respectively. The analysis results show that the constraint system can effectively limit the longitudinal vibration of girder by tower-girder restraints by compared to the longitudinal floating system, but the safety factor against cable sliding is larger; tower deformation is smaller; bending moment of girder is smaller and displacement demand of expansion joint is also smaller. Therefore, from the view of structural seismic safety, it is recommended the longitudinal constraint system for self-anchored suspension bridge with multi-tower.