预应力箱型梁桥遭受超高车辆在不同位置撞击下的动态响应

Dynamic Response of the Pre-stressed Box Girder Bridge to Over-high Truck Impact Under Different Impact Position

随着城镇化的加快,超高车辆撞击城市预应力箱型桥梁上部结构的事故时有发生。因此,有必要对此类撞击事故的动态响应进行研究。运用LS-DYNA建立了精细化T型梁桥上部结构的三维分离式模型,与罐体模型进行碰撞分析。与相应试验结果进行了对比,验证了LS-DYNA模拟此类撞击的正确性。运用LS-DYNA建立了精细化预应力箱型梁桥上部结构的三维分离式模型,分别建立了三种工况下车辆与桥梁上部结构碰撞的耦合模型,由计算结果可以看出三种工况下桥梁损伤的位置和状况大致相似,撞击位置距离支座越近,桥梁损伤就越严重。结果表明:撞击位置距离支座越近,碰撞力越大,撞击区域位移就越大。因此,超高车辆撞击预应力箱梁考虑最不利情况时,应研究车辆撞击桥梁支座处的破坏情况。

With the acceleration of the urbanization, the accidents of the over-high truck impacting the pre-stressed box girder bridge superstructure have occurred. Therefore, it is necessary to study the dynamic response of this kind of the impact. A three-dimensional separation model of the fine T bridge superstructure is established by LS-DYNA, and the collision analysis of tank and the T bridge is made. The accuracy of the LS-DYNA simulation was verified by comparison with the experiments. The three-dimensional separation model of the fine pre-stressed box girder bridge superstructure is established by LS-DYNA, and the coupling models of the vehicle and bridge superstructure under three working conditions are established respectively. Through the calculation results can be seen in the bridge damage location and condition are roughly similar. The more close the impact position to the bearing, the more serious damage to the bridge. The results show that the more close the impact position to the bearing, the greater the impact force and the greater the displacement of the impact area. It can be Concluded that the impact of the high vehicle impact on the pre-stressed concrete box girder, the most unfavorable situation should be considered to study the failure of the vehicle impact bridge bearing.