| In this paper, a study is made deeply on the ship-against-bridges problems and the risk assessment. The ship-against-bridges problems involve many fields such as bridgework, naval architecture, collision mechanics, ship driving and collision prevention, safety management, risk assessment, economics and environment protection. It is a typical subject in the intersect field. In China because the bridge building has been expanded to the mouth of the rivers and the sea banks, there is an increased number of the ship-against-bridges accidents. So it is necessary to make further related researches on the ship-against-bridges accidents in the conditions of increased potential ship-against-bridges risks.The paper reviewed and summarized the researches and progress on ship-against-bridges problems both at home and abroad, including the researches on the mechanical ship-against-bridges models, the risk assessment of the ship against bridges (including the ship against-bridges probability, consequence and the risk principles), researches on the ship-against-bridges accidents, the design methods of preventing ship collisions on bridges and researches on the ship collisions on bridges.Based on the extensive investigations, China' s first database SCB(Ship Collision with Bridge) of the ship-against-bridges accidents was set up with the consideration of consistency with the international accidents database of the ship against bridges, which has become the valuable information source for the further study on theship-against-bridges problems. The SCB database includes 213 accidents took place in the waters of Chang Jiang River, Heilongjiang River, Zhu Jiang River of China. By the statistical analysis of the time distribution of the accidents, the accidents reasons, and the relationships between the accidents and the ship type, the accidents and the bridges, some important conclusions are made. In addition, the analysis of the ship-against-bridges accidents such as visibility, day and night, upriver ships and downriver ships are performed. A database management software of the ship-against-bridges accidents is developed, which can be used for consulting, making statistics and printing, and very convenient for all kinds of users.Based on the data in the accidents database SCB of the ship against bridges and the analysis of the probability of the ship-against-bridges accidents of the 12 typical bridges over Chang Jiang River and Heilongjiang River, a simple probability model of ship against bridges is suggested, which fits for the actual conditions of China on the basis of the contrastive analysis of each existed probability model of the ship against bridges. An observation on ships passing under the bridges of Chang Jiang River in Nan Jing has been made on the spot, and the normal distribution laws of the course distribution were proved and the collision influence factor of the bridge was proposed.In this paper, an approach of the systematic artificial neutral net was introduced into the analysis on the ship-against-bridges probability with a computer programs. Based on the basic data of thepresent 12 typical bridges as the sample, 4 chief influential factors as the input coefficient, such as the bridge span, the water flow rate, the incline angle between water flow direction and the direction normal to bridge axis, and the curve in the course near the bridge area, with the ship-against-bridge probability as the output coefficient, the intelligent judging system of the ship-against-bridges probability reflecting the influence of the above input parameters is obtained after training.In this paper, a general framework for the risk analysis of the ship impact against bridges is set up. In evaluating the consequence of the ship-against-bridges accidents, a concept of "equivalent weight of consequence" has been put forward , which will become a guide for the research and application concerned in the future.Based on the above researches, a preliminary risk assessment of Harbin Song Hua River Slope Roa...
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