基于风险评估的桥梁船撞角度分析

近年来世界范围内发生了多宗船撞事故,合理地对桥梁进行船撞风险评估是非常重要的。AASHTO船撞设计指南中模型是最常用的计算桥梁年倒塌频率的模型。然而,与桥梁倒塌频率有关的船撞力计算公式中只考虑了船舶的速度,并未考虑船舶撞击桥梁的方向。以椒江二桥为工程背景,采用美国AASHTO船撞设计指南中计算桥梁年倒塌频率的模型对桥梁船撞角度进行分析。在未考虑防撞系统和考虑防撞系统情况下,分析船舶撞击桥梁时的角度对椒江二桥的年倒塌频率的影响。结果表明,在未考虑防撞系统情况下船舶撞击椒江二桥的角度不能超过31°,在考虑防撞系统情况下船舶撞击椒江二桥的角度不能超过37°,否则会超过椒江二桥可接受的年倒塌频率。建议对超过该角度的船舶进行警示,以保证桥梁和船舶的安全。

Angle Analysis of Vessel Colliding with Bridge Based on Risk Assessment

In recent years,ship-bridge collision accidents have been widely reported worldwide and it is of great importance to evaluate the risk of shipbridge collision. The AASHTO model in the guide specification and commentary for vessel collision prevention design of highway bridges is the most common one to calculate the collapse probabilityof bridges. However,the ship-bridge collision force formula is only related to the speed of the ship,but fails to consider the direction of ship-bridge collision. The angle of ship-bridge collision is analyzed with AASHTO model. Taking the second Jiaojiang Bridge as the engineering background,the ship-bridge collision angle is analyzed to address the influence of collapse probability with and without anti-collision system. The results show that the angle of ship-bridge collision should not exceed 31 degree without anti-collision system,while the angle of ship-bridge collision should not exceed 37 degree with anticollision system. Otherwise,the collapse frequency of second Jiaojiang Bridge could exceed the accepted risk criterion. Thus,it is suggested that any ship should be warned once the ship passes the bridge at exceeded angle.