山区河流典型桥梁船撞概率分析模型比较

Comparison of ship collision probability analysis models for typical bridges in mountainous rivers

船撞桥概率是多学科交叉融合、多因素影响的复杂研究,目前山区河流中梁桥和拱桥在计算船撞桥概率选取规范模型时不太相同。现有船撞桥概率模型及适用条件有所不同,采用美国AASHTO规范模型、LARSEN模型以及三概率参数积分模型,开展船舶对山区河流典型桥梁撞击概率及规律分析。通过分析连续钢构梁桥、上承式拱桥两种桥型的桥在最高、最低通航水位下涉水桥墩的年撞击概率,分析水位变化对年撞击概率的影响规律,得到山区河流梁桥和拱桥的模型适用性。结果表明,三种规范模型下的年撞击概率皆随着通航量的增加而不断增加,AASHTO模型与三概率参数模型,对于梁桥的概率计算结果变化趋势大致相似;对于拱桥,三概率参数积分模型对拱桥撞击横向、纵向位置的变化较为敏感,更适用于山区水位变化较大的拱桥。成果可为不同桥型在船撞概率模型选取提供参考。

The probability of ship-bridge collision is a complex study of multi-disciplinary cross-integration and multi-factor influence.At present,the probability of ship-bridge collision calculated by beam bridge and arch bridge in mountain rivers is not the same when selecting the standard model.The existing ship collision probability models and applicable conditions are different,so the AASHTO specification model,LARSEN model and three probability parameter integral model are used necessarily to analyze the probability and law of ship collision with typical bridges in mountainous rivers.By analyzed the annual impact probability of wading piers of continuous rigid frame bridge and deck arch bridge under the highest and lowest navigable water levels and the influence of water level change on the annual impact probability,the model applicability of bridge and arch bridge in mountainous rivers was obtained.The result shows that the annual impact probability under the three standard models increases with the increase of traffic volume.The AASHTO model and the three probability parameter model have similar trends in the probability calculation results of the beam bridge.For arch bridges,the three-probability parameter integral model is more sensitive to the changes of the transverse and longitudinal positions of the arch bridge,and is more suitable for arch bridges with large water level changes in mountainous areas.The reference for the selection of ship collision probability model for different bridge types can be provided by the result of this paper.