某航道桥下部结构受船舶撞击后安全性能评估及修复

为评估航道桥下部结构的船撞安全性,以遭受船撞的某内河航道桥为研究对象,采用有限元方法和相关规范计算受撞击的5号桥墩自身水平抗力、船撞力、墩顶位移,并从墩顶位移和桥墩抗力两方面对受撞桥墩的安全性进行评估。结果表明:5号桥墩的横桥向和顺桥向抗力均由桩基强度控制,分别为2528 kN和1142 kN;事故船撞击工况下,墩顶最大横桥向和顺桥向位移分别为7.6 mm、13.4 mm,满足位移限值要求;沿横桥向和顺桥向的船撞安全系数分别为1.67和0.94,顺桥向的自身抗力不足以抵抗瞬时船撞力,导致桥墩桩基础受损,建议采用增大截面法对受损桩基础进行加固补强,并设置独立防撞墩以保障桥梁结构安全。基于分析过程,总结了桥梁下部结构船撞安全评估的一般流程。

Safety Evaluation for Substructure of a Navigational Channel Bridge After Ship Collision and Repairs

To evaluate the safety of the substructure of navigational channel bridge after hit by a ship,a bridge crossing river navigational channel that had experienced a ship collision was taken as the study object.The finite element method was used and relative codes were referenced to calculate the horizontal resistance of the pier No.5,ship collision force and the pier-top displacement,and the safety of the pier hit was evaluated from two aspects of pier-top displacement and pier resistant force.The results show that the resistant forces of the pier No.5 in both the transverse and longitudinal direction are controlled by the strength of the pile foundation,with values of 2528 kN and 1142 kN,respectively.In the loading case of ship collision,the maximum pier-top displacements along the transverse bridge direction and longitudinal bridge direction are 7.6 mm and 13.4 mm,respectively,meeting the requirements of the displacement limits.The ship collision safety coefficients along the transverse and longitudinal directions are 1.67 and 0.94,respectively,the resistant force along the longitudinal direction is not sufficient to resist the transient ship collision force,causing the damage of the pile foundation of the pier.It is suggested to strengthen the damaged pile foundation by the way of enlarging its cross section,and adding independent anti-collision piers to ensure the structural safety of the bridge.Based on the analytical process,the general flowchart of the safety evaluation of the substructure of a bridge after ship collision is summarized.