曲线箱梁桥上下部同步纠偏施工与监测技术研究

Study on the Construction and Monitoring Technology of Simultaneous Upper and Lower Deflection Correction of Curved Box Girder Bridges

针对软土区曲线箱梁桥结构上下部同时出现偏位的纠偏问题,以某曲线箱梁匝道桥为对象,提出在桥面与墩底同步顶推的纠偏技术。设计了将墩柱与箱梁临时固结后,通过桥面伸缩缝处千斤顶的顶推与牵引,结合墩底承台处千斤顶的顶推实现上下部同步纠偏的施工方案。为保证结构安全与准确复位,设计了综合考虑上下部结构位移与应力变化的施工监测方案。依据桥面伸缩缝位移、墩顶位移与墩底位移之间的变形协调关系,实现对纠偏施工过程的精准控制。现场实测结果表明,采用所设计的上下部同步纠偏方法及相应的施工监测控制方案,能够在确保结构安全的同时,高效实现曲线箱梁的纠偏目标,可为同类工程提供参考。

In order to solve the problem of simultaneous upper and lower deflection of curved box girder bridge structures in soft soil areas,a curved box girder ramp bridge is taken as the object and the deflection correction technology of synchronous jacking at the bridge deck and pier bottom is proposed.After the temporary consolidation of the pier and box girder,the construction plan was designed to achieve simultaneous upper and lower deflection correction by jacking and traction at the expansion joint of the bridge deck,combined with jacking at the bearing platform of the pier.In order to ensure structural safety and accurate restoration,a construction monitoring scheme was designed to take into account the displacement and stress changes of the upper and lower structure.Based on the deformation coordination relationship between the bridge deck expansion joint displacement,pier top displacement and pier bottom displacement,accurate control of the deflection correction construction process is achieved.The results of field measurements show that the designed method of simultaneous upper and lower deflection correction and the corresponding construction monitoring control scheme can ensure structural safety while efficiently achieving the deflection correction target of curved box girder,which can provide reference for similar projects.