面向双层交通的混凝土箱梁抗弯性能试验研究

EXPERIMENTAL STUDY ON THE BENDING PERFORMANCE OF CONCRETE BOX GIRDER ORIENTED TO DOUBLE TRAFFIC

利用混凝土箱梁整体受力性能优势,将其顶、底板均作为桥面系实现双层交通,是解决城市土地资源紧张和交通堵塞的不错选择。设计了1∶6比例双层交通混凝土箱梁模型,在弹性工作状态下进行了双层均布荷载试验研究,在双层集中荷载作用下进行了受弯全过程破坏试验。试验研究了关键截面应力-应变发展规律、荷载-挠度曲线、抗弯承载力及其破坏模态等。结果表明:弹性工作状态下按照不同工况在箱梁顶、底板施加均布荷载作用时,存在不同剪力滞效应;双层集中荷载作用破坏性试验证实了宽跨比、高跨比均较大的双层交通混凝土箱形截面梁的受弯破坏过程可分为弹性阶段、弹塑性发展阶段、最终破坏阶段。相关结论可为双层交通混凝土箱梁桥的设计和应用提供试验数据和理论依据。

Due to the advantage of overall mechanical performance of concrete box girder, it could be a good choice to solve the problem of limited urban land resources and traffic jam by taking its roof and floor as deck system to achieve double deck traffic. A double traffic concrete box girder model with a scale of 1：6 was designed. Tests under the double uniformly distributed load in elastic state, and bending failure tests under the concentrated load were carried out. The development of stress and strain, load deflection curve of key section, the flexural bearing capacity and failure mode was studied. The results show that there is different shear lag phenomenon under different load conditions in the elastic working state. In double deck concentrated load experiment, the test confirmed the bending process of double traffic concrete box girder with large wide-span ratio and depth-span ratio can be divided into the three phases, i.e., elastic, elastic-plastic and destruction phases. This research is expected to provide experimental data and reference for design and application of double transportation concrete box girder bridge.