周邓快速路跨浦东运河上层桥关键技术研究

Research on Key Technologies for Upper Bridge over Pudong Canal on Zhoupu - Dengzhen Expressway

摘要:

以上海市周邓快速路（S3—G1503）跨浦东运河上层桥65 m+120 m+65 m连续钢箱梁为对象，重点解决高腹板稳定、4.75 m大挑臂受力及正交异性桥面板应力控制3项关键技术。采用纵向有限元模型，按板块屈曲安全度νmin≥1.35、水平加劲肋安全系数γ≥6.0优化6 m高腹板，确定设置4道水平加劲肋；利用Sack公式计算挑臂根部内力；将主梁体系与桥面体系计算结果线性叠加来控制桥面板应力，以盖板体系R≥20 m、Δ≤0.4 mm进行桥面板刚度控制。结果表明：腹板最弱板块的νmin=1.81，γ=36.4；挑臂根部组合应力113 MPa；桥面板叠加拉应力228.3 MPa、压应力208.7 MPa，R =26.4 m，Δ=0.146 mm，均满足规范，可为同类大跨钢箱梁桥设计提供技术参考。

Abstract:

Taking the 65 m+120 m+65 m continuous steel box girder of the upper bridge over the Pudong Canal on Zhoupu - Dengzhen Expressway (S3 - G1503) in Shanghai as the study object, the focus is on solving three key technologies of high web stability, force on the 4.75-m large cantilever and stress control of orthotropic bridge decks. A longitudinal finite-element model is used to optimize the 6-m high web according to the safety degree νmin ≥ 1.35 of web buckling and the safety factor γ≥6.0 of horizontal stiffening ribs, and it is determined to set up four horizontal stiffening ribs. The internal force at the root of the cantilever is calculated using the Sack formula. The stress of the bridge deck is controlled by linearly superimposing the calculation results of the main beam system and the bridge deck system, and the stiffness of the bridge deck is controlled by the cover plate system with R≥20 m and Δ≤0.4 mm. The results show that the weakest plate in the web has?νmin = 1.81 and γ = 36.4. The combined stress at the root of the cantilever is 113 MPa. The superimposed tensile stress of the bridge deck is 228.3 MPa, and the compressive stress is 208.7 MPa, R=26.4 m and Δ=0.146 mm, all of which meet the specifications and can provide the technical reference for the design of similar long-span steel box beam bridges.