考虑挠度和转角约束的桥面连续段受力计算方法研究

Study on force calculation method of continuous deck segment considering the constraints of deflection and rotation

采用桥面连续构造替代伸缩装置是降低简支梁桥维护成本、实现接缝终身免维护的有效途径,但现有桥面连续段受力计算方法过高估计其承受的荷载,使得设计配筋量显著增加,不仅提高了建造成本,而且增大了桥面连续段对主梁的约束作用,改变了桥面连续构造的受力状态,难以满足对其进行合理设计的需求。针对此问题,提出一种基于主梁对桥面连续段挠度和转角约束下二者变形协调的桥面连续段受力计算方法,并将计算结果与试验值以及现有桥面连续段受力计算方法所得结果进行对比。结果表明,所有桥面连续段受力计算方法所得结果均大于试验值,但本文所提出的方法计算结果最小,与试验值吻合最好,钢筋应力的误差范围在1766%~3027%,验证了所提方法的有效性。最后以桥面连续混凝土简支T梁桥为例,给出了便于应用的确定桥面连续段受力的方法,且所提方法物理意义清晰,计算流程简便,预测精度更高。

The use of continuous deck structures instead of expansion joints is an effective approach to reduce the maintenance cost of simply supported girder bridges and achieve lifetime maintenance-free joints.However,the existing calculation method overestimates the bearing force of the continuous deck segment,resulting in a significant increase in the reinforcement of the design.This not only increases the construction cost,but also increases the restraining effect of the continuous deck segment on the girder and changes the force state of the continuous deck structure,making it difficult to meet the rational design requirement.To solve this problem,a calculation method for the bearing force of the continuous deck segment was proposed by considering the deformation harmony of the deck and the girder under the constraints of deflection and rotation,and then the calculated forces by the proposed method were compared with the experimental values and the results obtained from the existing calculation methods.The results show that the forces obtained by all the calculation methods are greater than the experimental values,with the results of the proposed method being the smallest and showing the greatest agreement with the test values,and the error range of the reinforcement stress is from 1766%to 3027%,which validates the effectiveness of the proposed method.Finally,the practical method for determining the bearing force of the continuous deck segment was presented by taking the continuous deck concrete simply supported T-girder bridge as an example.The proposed method has a clear physical interpretation,a simple calculation process,and a higher prediction accuracy.