大跨小半径变宽度三跨变截面预应力混凝土连续梁设计与施工

Design and Construction of Long-span Small-radius Variable-width Three-span Variable Cross-section Pre-stressed Concrete Continuous Girder

娄江大桥为娄江航道上一座(83+145+83)m三跨变截面预应力混凝土连续箱梁桥,具有大跨小半径变宽度结构特点,常规的施工方案难度和风险大。项目中跨采用挂篮节段悬浇施工,边跨采用支架节段现浇施工,成功解决了不断航情况下大跨小半径变宽度三跨变截面预应力混凝土连续梁桥的设计及施工方法问题。建议利用梁格模型或者空间网格模型作为补充验算,对空间梁单元模型所采用的经验系数进行修正后进一步验算。

Loujiang River Bridge is a (83+145+83)-m three-span variable cross-section pre-stressed concrete continuous box-girder bridge on the waterway of Loujiang River. It has the characteristics of large-span small-radius variable width structure. The conventional construction schemes are difficult and risky. In this project, the segment cantilever pouring construction of form traveler is adopted for the middle span and the bracket segment cast-in-place construction is adopted for the edge span, which successfully solves the of design and construction problems of long-span small-radius variable-width three-span variable cross-section pre-stressed concrete continuous girder bridge under the continuous navigation conditions. It is proposed to use the beam grillage model or spatial mesh model as an added checking calculation. The empirical coefficient used for the spatial beam element model is further checked and calculated after amendment.