现有铁路钢桥的评估

对现有铁路钢桥进行一系列的动力试验、加速度测量、评估、有限元模拟和安全指数计算。采用专门列车进行动力试验,并获取动力参数。这些参数还可用于建立桥梁的有限元模型。如果模型能够反映实际工况,就能用于计算每种工况下桥梁结构的安全指数。这些安全指数可用于计算杆件的破坏可能性,因此可采用本模型评估桥梁的可靠性。通过了解现有桥梁结构的实际工况,本研究可为新的货运列车重级荷载研究提供可靠依据。

Assessment of Existing Steel Railway Bridges

A series of dynamic tests,acceleration measurements,evaluation,finite element model simulations and safety index calculations were performed on existing steel railway bridges giving service on railway network.Dynamic tests were fulfilled by using a special test train on these bridges to obtain the dynamic parameters and these parameters were then used to refine the finite element models of the bridges.Once the models have been updated to represent the actual condition,safety indices were calculated for structural components of the bridges for each proposed loading condition.These safety indices were used to calculate failure probabilities of structural members.As the final step,system reliability of the bridges was evaluated based on proposed system models of the bridges.It is believed that this study will provide a reliable background for proposed heavier axle loads resulting from new freight trains by realizing the current condition of bridge structures.