曲线连续梁转体施工中不平衡力矩与配重技术研究

Research on Unbalanced Moment and Counterweight Technology in Rotating Construction of Curved Continuous Beams

摘要:

为解决曲线连续梁转体施工中不平衡力矩控制难题，以跨包兰铁路特大桥“40 m+56 m+40 m”的预应力混凝土连续梁为研究对象，采用球铰转动测试法，实测22#墩和23#墩的不平衡力矩、摩阻力矩及偏心距等关键参数。结果表明，2墩转体梁的球铰摩阻力矩均小于不平衡力矩，重心均偏向大里程侧，初始偏心距分别为9.9 cm 和6.7 cm。经方案比选，采用梁体纵向倾斜配重方案，在22#墩小里程侧布设2.5 t配重，将偏心距优化至6.5 cm，23#墩无需配重。最终提炼出大跨度曲线转体梁桥“偏心距超阈值时需有针对性地配重，达标则免配”的配重调控规律，可为同类工程的施工提供技术参考。

Abstract:

To address the challenge of unbalanced moment control in the rotating construction of curved continuous beams, and taking the 40 m+56 m+40 m prestressed concrete continuous beam of the super-large bridge spanning the Baotou-Lanzhou Railway as the research object, the spherical hinge rotation test method is used to measure the key parameters such as unbalanced moment, friction resistance moment and eccentric distance of Piers 22# and 23#. The results show that the spherical hinge friction resistance moments of the two pier rotating beams are all less than the unbalanced moment. The center of gravity is all inclined towards the long mileage side. The initial eccentric distances are 9.9 cm and 6.7 cm respectively. After scheme comparison, the longitudinal tilting counterweight scheme for the beam body is adopted. A 2.5-t counterweight is arranged on the short-distance side of Pier 22, and the eccentric distance is optimized to 6.5 cm. No counterweight is needed for Pier 23. Finally, a counterweight control rule is extracted for long-span curved rotating beam bridges. When the eccentric distance exceeds the threshold, the targeted counterweights should be added. If meeting the standard, no counterweight is required, which provides the technical reference for the construction of similar projects.