| The group of piles-cap structure of the lower part of the cross-sea bridge is subjected to the action of waves and currents in the marine environment,and its stress state is very complicated.Therefore,studying the force under the combined action of the wave-current of the group of piles-cap structure has an important guiding role to actual engineering.This paper is based on the country's vigorous development of the marine economy and the comprehensive promotion of marine science as the background,relying on the National Natural Science Foundation project “Study on calculation method of wave-current force of pile-bearing-bridge pier integral structure of sea-crossing bridge”,studying the stress characteristics and interaction of piles-cap composite structures under the combined action of waves-currents of the different geometric shapes of the group of piles-cap structure,comparing its theoretical calculation methods.The main contents are as follows:(1)Through the review of relevant domestic and foreign literatures,discussing the research purpose and significance of group piles-cap structure under the combined action of wave and current,and summarizing the current development status of wave-current force.(2)Based on the method of physical experiment,the variation of wave height and velocity field after the coupling of different waves and different flow rates is studied.The theoretical formula is verified by comparing the theoretical value with the experimental value.(3)The stress characteristics of the forward wave flow force and the floating impact force of the different shapes of the caps under the impact of the wave-flowing space are studied,as well as the influence of the relative water flow rate and the relative wave height.The difference between the the experimental values and the calculated results obtained by Morison equation and diffraction theory under the action of wave water pressure is studied.These differences are caused by the shape of different caps,the influence of the lower group piles on the cap and the unreasonable linear superposition of the wave current,Lead into the correction coefficient K' to correct the differences.The impact force with the relative water flow velocity and relative wave height is studied when the cap is impacted.(4)According to the linear wave theory and the Stokes 5th wave theory,the theoretical values by Morison equatian of group of piles in different lower caps after different water depths and different wave conditions are calculated,and compared with the experimental values.After the wave is coupled with the water flow,the rationality of the linear superposition is analyzed by comparing the experimental linear superposition value of thewave force and the water flow force with the experimental value of the wave current force.The effects of relative water flow rate and relative wave height on the force of group piles are analyzed. |
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