Impact Analysis And Collision Avoidance Of Hanqiao Construction And Ship Completion

With the rapid development of bridge construction in China and the rapid advancement of urbanization,more and more inland river bridges have emerged.The upgrading of inland waterways and the increasing number of ships have made the ships have a higher requirement for navigation,which increases the probability of the ship-bridge impacts.In order to ensure the safety of inland river bridges during construction and operation,the response of the temporary steel piers in construction and permanent concrete piers in operation to the impact of the ship need to be studied and analyzed.Although scholars have made some researches on the field of ship-bridge impacts,there are few studies on the ship-bridge impacts under typical conditions of construction during the construction period.This research remains to be further studied.This article is based on the engineering background of Liuyang River Han Bridge in Changsha city(steel truss curved beam bridge),the FEM simulation calculation and prevention and control measures research have been done with the basis of the hydrological conditions,navigation capabilities and typical conditions of construction for Hanqiao under ship impact.The main research work of this paper is following:1.To collect domestic and foreign cases of ship-bridge impacts and the literature on the current status of bridge-ship impact research,to explain the backgrounds and significances of the research on bridge-ship impacts,and overview the main research work on the bridge-ship impacts of Liuyang River in this paper.2.To summarize the basic theory of bridge-ship impact and the calculation norms on this theory in each country,and compare the advantages and disadvantages of each theoretical norm.In China's norms,the value of ship impact force is relatively small.And the impact value in China's norms is difficult to define.The American engineering community put forward the AASHTO specification formula by summarizing the research results of various countries.The formula is relatively complete and covers the advantages of national regulations.Finally,the America AASHTO specification is screened as the theoretical formula for the analysis of bridge-ship impacts of Liuyang River Hanqiao in this paper,which lays a theoretical foundation for the research.3.To introduce the construction process of Liuyang River Han Bridge detailedly,to establish a structural finite element analysis model of the construction phase,and simulate the typical working conditions through the finite element in the construction phase,which lays the foundation for the later analysis of the response analysis of the bridge-ship impact on the Liuyang River Han Bridge during the construction phase.4.The Midas finite element model is established for the typical conditions of the cantilever fourth stage and the hoisting fifth stage in the construction phase of Liuyanghe Han Bridge,which is based on the American AASHTO formula and the Hanqiao hydrological conditions and navigation capacity,The temporary piers of HanQiao in the construction phase were simulated and analyzed under the impact of a 500t ship under different water level conditions(flood period,normal water level,and dry season),and the temporary pier risk prevention and control measures were proposed through calculation and analysis,it was concluded that in the fourth stage of overhanging,the Hanqiao had the greatest impact on the mid-span displacement when the bridge-ship impact happened.In the fifth stage of lifting,Hanqiao had the greatest impact on the bending moment of the pier when the bridge-ship impact happened.5.Establish the Midas finite element model for the bridge stage of Hanqiao.Based on the AASHTO formula and the Hanqiao hydrological conditions and navigation capacity,to simulate of the response analysis of the permanent pier after the completion of the Han Bridge under three different altitudes under the impact of a 500t ship.In the bridge stage of Hanqiao,the impact on the mid-span shear force is greatest when the ship hits the bridge.Finally,collating the anti-collision measures of Hanqiao piers provides a certain reference value for future anti-collision analysis similar to Hanqiao(steel truss curved beam bridge).