Research On The Key Technologies Of Bridge Navigation Evaluation

With rapid economic development, Chinese traffic modernization has made significant progress. The number of river bridges which link the transport network cross navigable river is rapidly increasing; these river bridges become important symbols of Chinese traffic modernization, and impulse Chinese economy.With the growth of river bridges, ship navigation flow density is increasing year by year. Therefore, piers of the bridges at the river will have a greater prejudice on ship's normal, particularly in the greater impact of the floods, leading to changes on the bridge site topography and river navigational environment. In order to analyze and research the probable influence, to grasp the tendency and its influence factor when ships passing bridge comprehensively; to lead the passing ships scientifically and reasonably, to guarantee the safety of navigation and bridge, it is extremely essential to research the navigation situation in bridge site section of rivers.This paper bases on a research project, "Rearch on key technologies of inland water fairway navigation " from the Ministry of Communication, and projects "Sutong Changjiang Road Bridge Actual Ship Experiment and Simulating Study","The research on the disable drift influencing the Su Tong bridge"which is accepted by the Navigation College of WuHan University of Technology. The researches include the following main parts:(1) According to the evaluation of the domestic and international factors on indicators of the impact of shipping safety and the research results of the survey statistics, the set of indicators of the risk factors of the evaluation criteria are established. Based on this evaluation, the risk factors of the evaluation criteria subset of the membership table are determined; the single factor fuzzy evaluation model is established; based on the fuzzy single factor evaluation model, and the weight indicator of combine factors analysis, a multi-level, multi-target fuzzy comprehensive evaluation mathematics model of environmental risk around the bridge is established. (2) Through the tests of large-scale pushers and large sea fleet manipulation in a bridge area, the ship's passing tracks are measured. Based on the ship maneuverability theory, a ship drifting mathematical model is set up which can be used to identify the various ship's safety passing width.(3) Under the existing bridge construction to the actual situation, through the flume experiments, the formula of flow width between the fairways sideline and bridge piers is given.(4) According to the ship maneuverability theory, this paper sets up a ship's drifting mathematical model about the ship uncontrolled. Applying mathematical model of a typical large sea-going and river pushing fleet in the most adverse environmental conditions in different uncontrolled locations, the paper gives theoretical analysis and calculations on tracks and related parameters. According to two stages of inertial deceleration period and drift period, the paper calculates the transverse drift distance, drift time, movement direction, rate after ship out of control in the different environmental conditions and different uncontrolled locations.By analyzing the drift state of uncontrolled ship, the uncontrolled regional and pier collisions position are determined; the collision probability after the ship out of control is caculated. Based on the calculation results, corresponding measures to prevent or reduce collision of uncontrollable ship with bridg are brought up.(5) Using Visual C + + to produce visual interface procedure, and by making use of these mathematical modeles, the tracks of the different ships in different environmental parameters and manipulation parameters are simulated.Using MATLAB, the curves of the different wind speed, wind direction, flow velocity, flow course and ship drift are drawn.Through the actual ship test and flume tests , a possible mathematical model of ship passing the bridge for safety width is established. By calculation of the ship (team) safe width between bridge piers, the site of the bridge can be optimized .