钢管混凝土劲性骨架提篮拱桥动力试验及车桥耦合振动分析

对跨径140 m的铁路钢管混凝土劲性骨架提篮拱桥进行全桥动力试验。采用脉动法测试其自振特性;动载试验中试验列车分别以不同速度匀速通过桥面及以一定速度在指定位置处制动,测试各工况下桥跨结构的应变、位移、加速度的时程响应,并将实桥测试结果与该桥的车桥耦合振动计算结果作比较分析。结果表明:该桥具有良好的竖向和横向刚度及结构强度,整体动力性能良好,而通过列车对桥跨结构有一定的冲击作用;实测动力响应及其动力系数结果与理论计算结果相符较好,两者随着列车运行速度的增大而呈现相同的规律性;列车运行具有较好的安全性与舒适度;该类型桥梁适用于大跨度铁路桥梁。

Dynamic Loading Tests and Vehicle-bridge Coupling Vibration Analysis of Concrete-filled Steel Tube Stiffening-frame Reinforced X-style Arch Bridge

Dynamic loading tests were made over a railway concrete-filled steel-tube stiffening-frame reinforced X-style arch bridge with the span of 140m.The free-vibration characteristics were tested with the microseism method.The dynamic responses of strains,displacements and accelerations of the structure were tested under the dynamic loads of the train passing through the bridge with different uniform velocities and the train braking at a specifed point on the bridge with some requied velocities.The test results of the real bridge and the calculated results of the train-bridge coupling vibration were analyzed together.It is demonstrated: The bridge is of sufficient structural strength,vertical rigidity and transverse rigidity,and is of entirely good dynamic characteristics;the passing train has the impacting function on the structure;the dynamic responses and coefficients measured on site match well with theoretical calculation,both show the same regularity against the increasing traveling velocities of the train;the passing trains have good safety and comfort performance;this type of bridge is suitable for long-span railway bridges.