The standard reconstruction of river-crossing bridges is an important component of waterway regulation projects,which has high investment and significant social impact.In waterway regulation projects,it is necessary to conduct a preliminary evaluation of the impact of navigation conditions on existing bridges.There are numerous river-crossing bridges along the Sushen Inner Port Line waterway,in the evaluation process,for bridges with significant difficulty in renovation due to insufficient clearance dimensions,the method of calculating the navigation capacity of the bridge area waterway is adopted to quantitatively analyze the degree of obstruction to navigation of the bridge.Theoretical analysis can be used to calculate the navigation capacity of the bridge area waterway.On the basis of the conventional channel capacity calculation method for the tidal section outside the gate,the navigation guarantee rate of each water level can be inferred using the cumulative frequency curve of tide level.The navigation guarantee rate is used as a correction coefficient to calculate the navigation capacity of the bridge area waterway.By comparing the calculated capacity of the waterway with the planned and designed freight volume,the necessity and urgency of bridge reconstruction can be preliminarily judged.
river-crossing bridgeinland waterwaynavigation capacitywaterway planning and designnavigation guarantee rate