重载铁路机车牵引作用下简支梁桥墩顶纵向力分析

以重载机车牵引作用下新建重载铁路简支梁桥墩顶纵向力特征为研究对象,应用有限元软件建立梁-轨相互作用模型,开展重载机车牵引工况对墩顶纵向力影响的理论分析,并依托一新建重载铁路开展重载机车满级牵引试验验证。研究结果表明:在重载机车牵引工况下,桥墩刚度存在较大差异,刚度较大的墩台顶承担更大的纵向力;随着桥墩与机车牵引位置的距离增大,墩顶纵向力呈降低的趋势,机车在桥墩正上方牵引时墩顶纵向力达到最大值;重载运输中机车满级牵引计算分析时黏着系数宜按电力机车最大黏着系数选取;牵引工况下各桥墩顶纵向力为桥上竖向荷载(30 t轴重机车)的10%~15%,但小于设计活载(ZH,z=1.2)的10%。

Analysis on Longitudinal Force on Pier Top of Simply Supported Girder Under Locomotive Traction of Heavy Haul Railway

The characteristics of longitudinal force at the pier top of a new heavy haul railway simply supported girder bridge was studied under the loads of the traction of heavy haul locomotive.The girder-rail interaction finite element model was established,and the theoretical analysis of the influence of the traction condition of the heavy haul locomotive on the longitudinal force at the pier top was carried out.The full-stage traction test of the heavy haul locomotive was carried out on a new heavy haul railway.The results show that greater longitudinal force exists in the pier with greater rigidity under the traction of heavy haul locomotive,indicating there is a great difference between the piers.With the increase of the distance between the pier and the traction position of the locomotive,the longitudinal force at the pier top decreases.The longitudinal force of pier reaches its maximum value when the locomotive tracts directly over the pier.In the case of the full-stage traction of heavy haul locomotive,the maximum of adhesion coefficient of the locomotive should be selected in the traction calculation.In the loading case of traction,the longitudinal force of each pier is between 10%and 15%of the vertical loads caused by the 30 t axle load heavy haul on the bridge,but less than 10%of the designed live load(ZH,z=1.2).