三峡库区弯曲河段大偏角船桥碰撞力分析

为研究船舶在大角度和高流速下与大跨度斜拉桥发生的碰撞响应，结合国内外相关规范对船桥碰撞中最大撞击力计算方法和撞击方式，对内河航运过程中可能发生的碰撞角度和方式进行分析，并以重庆外环江津长江大桥作为依托工程，采用附加质量法建立了7 000 t级散货船和等比例斜拉桥模型，计算了船舶在四种通航水位下的正撞、侧撞和漂撞的最大撞击力，比较各规范的计算值与数值模拟结果，对不同情况下的计算结果进行对比研究。结果表明，国内外各规范更适用于船舶撞击桥塔，撞击点位于桥梁承台时最大撞击力将远高于规范计算值；在船舶与桥梁正面碰撞中，《美国公路桥梁设计规范》(American Association of State Highway and Transportation Officials, AASHTO)计算值与模拟值吻合程度高；在侧撞中，尤其在撞击角度为10°～25°时，建议采用《公路桥梁抗撞设计规范》;船舶漂撞桥塔产生的撞击力大约为正向撞击的1/4,该情况可采用《铁路桥涵设计规范》进行计算。多角度船桥碰撞研究结果可为三峡库区高变幅水位下船桥碰撞安全风险评估和桥梁抗撞设计提供参考。

Collision Force Analysis of Ship-Bridge with Large Deflection Angle in the Three Gorges Reservoir Area

For the study of ship under large Angle and high flow velocity and the collision response of large span cable-stayed bridge, combined with domestic and foreign relevant specifications for maximum impact force calculation method in ship bridge collision and impact, in the process of inland waterway transport possible collision Angle and the way carries on the analysis, and the outer ring of the Chongqing metro, Yangtze river bridge as the project The models of 7 000-ton bulk carrier and proportional cable-stayed bridge are established by using the additional mass method, and the maximum impact forces of forward collision, side collision and drift collision are calculated at four navigable water levels. The calculated values of each code are compared with the numerical simulation results, and the calculated results of each code under different conditions are compared. The results show that the domestic and foreign codes are more suitable for the ship impacting the bridge tower, and the maximum impact force is much higher than the calculated value of the code when the impact point is located at the bridge cap. In the case of a frontal collision between a ship and a bridge, the calculated values in AASHTO (American Association of State Highway and Transportation Officials) are in high agreement with the simulated values. In side impact, especially when the impact angle is 10°～25°, it is suggested to adopt the Specifications for Collision Design of Highway Bridges. The impact force caused by the ship''s floating collision with the bridge tower is about 1/4 of the forward collision, which can be calculated by the Code for Design of Railway Bridges and Culverts. The research results of multi-angle ship-bridge collision can provide reference for ship-bridge collision safety risk assessment and bridge anti-collision design under high fluctuating water level in the Three Gorges reservoir area.