既有钢桥工作状态模拟与剩余寿命评估

为评估既有钢桥的剩余寿命与使用安全,首先要建立能够精确模拟桥梁目前使用状态的工作模型,以准确计算桥梁中疲劳细节应力。在对桥梁交通荷载进行调查统计分析的基础上,建立能代表真实运营状况的车辆交通荷载谱,从而实现结构所承受荷载历程的模拟。以京九线南昌赣江桥为例,概要介绍既有钢桥工作模型与铁路列车荷载谱的建立,以及疲劳剩余寿命的评估结果。实例研究表明,为保证既有钢桥疲劳剩余寿命评估的可靠性,对结构工作状态和荷载谱进行精确模拟是十分关键的。

3D finite-element model simulation and remaining fatigue life assessment of existing steel bridges

In an assessment of remaining fatigue life and service safety,it is necessary to estimate the stress history at critical details throughout the existing steel bridges. In order to accurately calculate the stress at fatigue details, the 3-dementional finite-element models (3D FEM) which can reflect the actual mechanic behavior of existing steel bridges should be established.Based on the investigation and statistics analysis of the traffic load,the traffic load spectrum which can reflects the actual load history of structures is simulated.The establishment procedure of 3D FEM and train load spectrum is introduced through the example of Gan-jiang Bridge on Jing-jiu railway lines.The remaining fatigue life of Gan-jiang bridge is calculate based on S-N curve.Case study shows that accurate simulation of 3D FEM and train load spectrum is key step in assessment of remaining fatigue life for existing steel bridges.