山区通航桥梁船撞概率合理性研究

山区河流航道弯曲复杂并且多雾、滩多流急、船舶驾驶难度较大,加之理想桥位较为稀缺,往往在短距离内修建多座桥梁或将桥位布置在分汊河道上,极大增加了船舶碰撞桥梁的风险概率。目前业内广泛采用的美国AASHTO概率模型在计算偏航概率时,并未充分考虑山区河流建桥影响及航道特征等重要影响因素。通过分析桥梁间距、分汊等河道条件以及能见度对船撞桥风险的影响,提出了一个对偏航概率经验公式的修正计算方法。经选择山区航道上较为典型的石板坡长江大桥复线桥为代表,对修正前后的风险概率计算成果分析表明,考虑航道特征和建桥等影响后得到的风险概率评价结果较为合理。

Reasonable research on the possibilities of ship-bridge collision in mountain rivers

The channel in mountain rivers is complex and foggy, which lead to much difficulty for the ship driving. Moreover, by building more than two bridges in the short distance or laying the site in furcated rivers ,the possibilities of ship-bridge collision are increased due to the lack of ideal bridge sites. It was found that some important fators affecting ship-bridge collision risk due to mountain river characteristics and bridge construction are not available in the AASHTO possibility formula for the yaw, which is commonly used in the corresponding field of bridge engineering. The revised formulas relevant to risk possibilities were conducted by examining the performance of spacing between bridges, furcated river and visibility inducing the deviation from abnormal route of ship. The comparison of risk possibilities calculated by using unrevised and revised formulas were presented by taking the typical example of the second lane of Shibanpo Yangtze River Bridge and the results confirmed the reasonable and credible assessments with regard to the risk possibilities.