Research On Static And Dynamic Characteristics Of Arc Gate Support Structure Of High Arch Dam Surfure Spillway

Set the surface spillway at the top of the dam to discharge flood is the most common type of arch dam flood discharge.For high arch dams with high flood discharge requirements,the surface spillway undertake the main discharge capacity.With the development of arch dams,more and more high arch dams have built,which puts higher requirements on the flood discharge capacity of the dam,and the surface spillway structure is more larger and complicaed.For larger surface spillway sizes,arc gates are generally provided,It is necessary to add arc gate support structure composed of piers and support structure of the hinges to meet the requirements of arc gate installation and surface spillway discharge.Experience shows that the stress conditions of the piers,support structure of the hinges and the overflow weir are more complicated.If the shape design is unreasonable,it may cause partial concrete cracking in the surface spillway and affect the normal operation of the arch dam.In this paper,the numerical analysis method is used to systematically study the mechanical characteristics of the important parts such as the arc gate support structure and overflow weir of the high arch dam discharge surface.The main research contents and results are as follows:(1)Study the effects of main loads such as hydrostatic pressure,arc gate thrust,temperature load and seismic load on the stress and displacement of the arc gate support structure and the overflow weir;find that there are high tensile stress region on the inner side of the piers.The arc gate thrust and temperature load will cause the tensile stress of the pier to increase slightly;Under the action of hydrostatic pressure,the deformation of the top of the dam to the middle of the dam,causes a large tensile stress on the inner side of the pier.The seismic load has little effect on the tensile stress distribution on the sides of the piers.However,it will cause the maximum tensile stress value to increase.(2)When the hinges support structure are three types:dam top connection beam type,deep beam type and bracket type,Study the mechanical characteristics of the arc gate support structure under static and dynamic forces.The results show that the three types of hinges support structure,under static and dynamic forces.The results show that the three types of hinges support structure,arc gate support structure has different stress and displacement distribution,under static and dynamic loads.The stress distribution of the dam-top connected beam type of arc gate support structure is uniform and the force performance is optimal.The corbel type arc gate support structure has the largest deformation,high stress level,and the force performance is worse than the other two types.(3)Select the arc gate support structure of the dam-top connected beam with better mechanical behavior,study the shape of the piers.It is found that increase the thickness of the piers is more effective in reducing the tensile stress on the outer side of the piers.The effect of adding partial magnification structure with a small amount of concrete and increasing the thickness of the piers on the tensile stress on the inner side of the pier is similar.(4)Under the condition that the size of the surface spillway and the position of the center line of the surface spillway are unchanged,Study the influence of the relative position of the surface spillway and the dam on the stress of arc gate support structure and the overflow weir.It is found that the position of the surface hole has a greater influence on the stress of the arc gate support structure.the selection of a suitable surface spillway position can reduce the stress tensile level of of the piers and overflow weir.