三塔两跨悬索桥中央扣静力影响研究

Study on Static Influence of Central Buckle of Three-pylon Two-span Suspension Bridge

摘要:

中央扣常用于减少大跨悬索桥缆、梁之间的纵向相对位移。对于三塔两跨地锚悬索桥，中央扣对结构受力有更大影响。为了揭示中央扣对三塔两跨地锚悬索桥的静力影响、内在机理，以泰州长江公路大桥为基础，通过多个有限元模型的计算分析比较，研究了不同中央扣设置情形对中塔、主缆、加劲梁受力的影响。研究表明：三塔两跨地锚悬索桥的水平纵向索、双中央扣构造使得缆、梁、中塔间形成更直接的传力通道，减少了中塔上塔柱承担的活载剪力，对中塔内力位移、中塔处主缆抗滑安全、加劲梁弯矩均有较大改善。

Abstract:

The central buckle is often used to reduce the longitudinal relative displacement between the cable and beam of long-span suspension bridges. For the three-pylon two-span ground anchor suspension bridge, the central buckle has a greater impact on the structure stress. In order to reveal the static impact and internal mechanism of the central buckle on the three-pylon two-span ground anchor suspension bridge, based on the Changjiang River Highway Bridge in Taizhou, the effects of setting the different central buckles on the stress of the middle pylon, the main cable and the stiffening girder are studied through the computational analysis and comparison of multiple finite element models. The study shows that the double central buckle structure with horizontal longitudinal cables of the three-pylon two-span ground anchor suspension bridge makes the cable, beam and middle pylon form a direct force transmission channel, which reduces the live load shearing force born by the upper pylon of the middle pylon, and greatly improves the internal force displacement of the middle pylon, the anti-slip safety of the main cable at the middle pylon and the bending moment of the stiffener girder.