株洲湘江一桥桥墩抗船撞能力评估及防撞方案研究

Assessment of Ship Impact Capacity and Study of Anti-Impact Scheme for Piers of First Zhuzhou Xiangjiang River Bridge

船桥碰撞事故常有发生，为评估已建桥梁桥墩的抗船撞性能、指导防撞方案设计，以株洲湘江一桥通航孔8～10号桥墩为对象，建立有限元模型计算了桥墩在受到单位水平撞击力时最危险截面处产生的内力，进而根据相关规范，计算桥墩截面实际能够承受的水平撞击力；建模分析2000吨级船舶在各工况下撞击桥墩时实际产生的最大船撞力；根据两者计算结果差值评估桥墩的抗船撞能力，提出设置复合材料防撞系统方案并进行比较研究。结果表明：该桥桥墩的横桥向抗撞能力由9号墩强度控制，为11．03MN；船舶最不利工况撞击桥墩时产生的撞击力为13．55MN，超出桥墩极限抗撞能力；设置复合材料防撞系统后桥墩受到的水平撞击力可明显小于桥墩的水平抗力，从而保证桥墩结构的安全。

The accidents of ships impacting bridge piers have occurred from time to time. To assess the ship impact performance of the piers of existing bridges and to guide the design of the corresponding anti-impact schemes for the piers, the piers No. 8-10 of the navigable spans of the First Zhuzhou Xiangjiang River Bridge were taken as the research objects. The finite element models were established and the internal forces produced in the most dangerous sections of the piers of the bridge when the piers were subjected to the unit horizontal impact forces were calcu- lated. Further in accordance with the relevant codes, the horizontal impact forces that the sec- tions of the piers could actually sustain were calculated. More models were established and the maximum impact force actually produced in the piers when the piers were impacted by the 2 000 t ship under different load cases was analyzed. With reference to the differences of the two kinds of calculation mentioned above, the ship impact capacity of the piers was assessed and the scheme of the anti-impact system of composite material was proposed and was comparatively studied. The results of the calculation and study show that the ship impact capacity of the piers in the trans- verse direction of the bridge is governed by the strength of Pier No. 9 and the ship impact force in the pier is 11.03 MN. The impact force produced in a pier when the pier is impacted by ship un-der the worst load case is 13.55 MN and the force exceeds the ultimate ship impact capacity of the pier. The horizontal ship impact forces of the piers after the piers are furnished with the anti-im- pact systems of composite material are obviously less than the horizontal resistance forces of the piers and therefore, the structural safety of the piers can be ensured.