大跨钢桁梁桥涡激振动对高速列车行车性能的影响分析OA

High-speed trains impose stringent requirements on track alignment.Long-span bridges,characterized by flexible structures and low damping,are susceptible to vortex-induced vibration(VIV),leading to dynamic changes in deck alignment that compromise both operational safety and ride comfort of trains.To investigate the operational performance of high-speed trains on long-span truss girder bridges under VIV effects,this study selected a specific large-span combined railway-highway suspension bridge as its subject and established a wind-vehicle-bridge coupled vibration analysis model under VIV conditions.The finite element model of the bridge was calibrated based on health monitoring data.The analysis model was subsequently validated using measured track irregularities combined with relevant monitoring data.Finally,an investigation was conducted into the influence of bridge VIV on the dynamic response of trains,along with a discussion on the effects of factors such as train entry time,train speed,bridge vibration mode,VIV amplitude,and fluctuating wind.The results indicate that without VIV,the calculated train and bridge responses align well with monitoring data.Vertical VIV significantly impacts train vertical acceleration:higher bridge vibration frequencies and larger amplitudes exert more pronounced effects on train response.When determining VIV amplitude limits based on train response exceedance,the derived limit for second-order anti-symmetric vertical VIV may fall below code requirements,necessitating train speed control.When considering the combined effects of mean wind and fluctuating wind speed,all train response indicators increase with rising wind speed and torsional amplitude.For higher steel truss beam,the lateral component resulting from torsional vibration has a significantly large influence,causing the train's lateral acceleration to be the first to exceed the standard value.Therefore,the amplitude limit for torsional VIV is determined by the train's lateral acceleration,including fluctuating wind effects is essential for operational safety analysis under torsional VIV.The findings provide valuable references for wind-resistant design and VIV limit studies of long-span railway truss girder bridges.