Study On Local Scour Characteristics Of Caisson Under The Action Of Wave And Flow

The bridge of our country is developing towards the long span bridge.However,the basic structure is particularly important,and the foundation of caisson is widely used because of its strong overall performance,good stability,large bearing area and large bearing load.In the waters flow,waves,etc,due to the existence of the open caisson structure of flow field near the disturbance,increased around the open caisson velocity and the shear stress,the wave is directly increased sediment particle penetration seepage damage,the above will aggravate originally bed surface erosion,and the open caisson surrounding uneven scour pit,easily lead to problems such as instability and failure of open caisson,on people's life and property losses,Therefore,it is very meaningful to study the local scour characteristics around the caisson.Based on the numerical software Flow3 D by building uniflow numerical flume and numerical wave flume,by setting the long wave numerical flume and sponge layer structure,a stable and accurate numerical flow field is obtained.The model adopts RNG k-e model to simulate turbulence,and the calculation time is reduced by setting local encryption grid,and the reliability and accuracy of software calculation are verified through repeated numerical simulation verification.The results show that the numerical simulation software can effectively simulate the local scour characteristics of the sinking Wells under the action of single and wave.In this paper,in the simulation by changing various conditions such as inflow velocity,initial water depth,the size and wave parameter analysis of open caisson,and briefly expounds the flow field around the open caisson,water quality point velocity changes,the flow velocity field occurs when the scour occurs,shear stress and turbulence field flow field changes in the form,implements the microscopic analysis of the open caisson scour around water points;In this paper,we analyze the scour depth,the curve of scour change and the scour.Changes in the process of simulation of wave,the wave,wave form when across the open caisson has carried on the detailed description,through the numerical simulation results can be seen a series of waves and the result of the interaction between open caisson;And under the condition of the above two kinds of open caisson sinking process step by step analysis,analysis of the effects on the sand bed in the process of open caisson sinking,To obtain the scour rule in the sinking process of the caisson,and to know when the sinking process occurs and when the sinking occurs,it will be intensified.Finally in this paper,the erosion caused by wave are analyzed in theory,through the analysis of seepage field,and found that the seepage force and its important role in the process of erosion.During the scour process,the effect of percolation force on particles is an important condition for particle initiation.and in the analysis,it says the seepage damage caused by seepage force is an important factor to increase the maximum depth of local scour.This article through the analysis of the above three aspects,get the local scour property of the sink under the action of wave flow is obtained,through numerical simulation test,the design series conditions to provide certain reference in actual open caisson construction.