大跨连续梁先中跨后边跨合龙影响分析

Analysis on Influence of First Middle Span,Then Side Span Closure of Long-span Continuous Girder

先中跨合龙后边跨合龙的非对称悬浇连续梁桥,由于其特殊的浇筑及合龙方式,受力较为复杂。现运用有限元分析软件对合龙误差、合龙温度及合龙配重对桥梁成桥状态时的应力和变形的影响进行分析,发现合龙误差对桥梁成桥线性影响较为显著,较理想状况下位移可增大一倍左右;合龙温度会对桥梁支座产生顺桥向位移,施工中需提前设置预偏量;对中跨进行合龙配重可以有效减小墩顶不平衡弯矩,确保施工安全。

The asymmetric cantilever pouring continuous girder bridge with first middle span and then side span closure has a complex stress because of its special pouring and closure modes.The finite element analysis software is used to analyze the influences on the closure error,closure temperature and closure weight on the stress and deformation of the bridge completion state.It is found that the closure error has a significant influence on the bridge completion linearity.The displacement can be increased by about one time under the ideal condition.The closure temperature will produce the bridge direction displacement for bridge support.The pre-deviator should be set in advance during construction.The closure weight for middle span can effectively decrease the imbalance bending moment of pier top and the construction safety can be ensured.