Calculation Of Sub Stage Design Tidal Elements In Tidal Reach

At first, the hydrologic characteristics of the tidal reach and the current situation of design value research are elaborated. The methods to evaluate design tidal elements when the data are incomplete or inconsistent are studied in this paper, taking the tidal reach where Suzhou-Nantong Yangtze River Bridge will be constructed for example. And the methods of how to distinguish outlier in different parameter estimation methods are studied.The statistical characteristics of the sub stage maximum tidal level in bridge reach are analyzed. And found that the maximum tidal level in flood season should correct the inconsistency. Studied that the valid method , the mothod of extract trend from moving averages serial is chose for this reach.Approaching how to distinguish outlier from different parameter estimation methods. And used this standard (large than EX + 3 x σX) to estimate the design sub stage maximum tidal levels using the frequency analysis.An improved method to deduce design tidal level process is put forward, using both designs maximum anneal tidal level and design maximum annual tidal range. It makes the deduction on design tidal level process more reasonable than ever.Finally, taking into account the observed data of tidal level are much more integrated than observed data of tidal discharge and the correlative relationship are established based on large numbers of samples. Then, the sub stage maximum tidal discharges and tidal velocities are obtained according to the regressive equations and the observed tidal level, and the sub stage design maximum tidal discharges and tidal velocities are estimated by way of frequency analysis.The achievements of this paper will provide guidance for the preliminary design of Suzhou-Nantong Yangtze River Bridge, and the methods suggested here are applicable to other similar hydrological problems.