天兴洲大桥斜拉桥铁路结合桥面系模型试验研究

武汉天兴洲公铁两用长江大桥斜拉桥铁路桥面采用纵横梁体系的混凝土结合桥面板、有碴桥面、结合桥面板处于空间受力状态.针对铁路纵横梁体系的静活载效应、混凝土道碴槽板的弯曲应力及局部关键区域的受力行为进行专项模型试验,研究结合桥面系的力学行为、应力分布规律及应力传递路径等关键问题.试验结果表明:该桥铁路桥面采用的纵横梁体系混凝土板结合桥面系受力合理、响应明确,结构应力及刚度满足规范要求;卸载后残余应变、位移很小,结构处于弹性工作状态,混凝土道碴板未发现可见裂缝;结合桥面系的受力性能良好,设计合理可行.

Model Test Study of Composite Railway Floor System of Cable-Stayed Bridge of Tianxingzhou Bridge

The railway deck of the cable-stayed bridge of Wuhan Tianxingzhou Changjiang River Rail-cum-Road Bridge makes use of the composite concrete deck slabs and the longitudinal and transverse beam system, and the deck is an one to be arranged with ballast and the deck slabs will be in a state of complicated spatial stressing. For the deck of the bridge, the specialized model tests are made for the static live load effect of the longitudinal and transverse beam system, the bending stress and the mechanical behavior of the critical local areas of the concrete trough ballast slabs and several important issues like the mechanical behavior, stress distribution law and stress transmission paths of the deck are studied. The results of the test study show that the stressing conditions of the composite concrete slabs and the longitudinal and transverse beam system used for the railway floor system of the bridge are rational, the responses thereof are clear, the stress and rigidity of the structure can meet the requirements in the specification. The residual strain and displacement after unloading are very little, the structure is in the elastic working state and no visible cracks are found in the trough ballast slabs. The mechanical behavior of the composite floor system is good and the design of the floor system is feasible.