Analysis On Influence Of The Main Girder Drain Hole Sizes Of Deep-hole Plane Steel Gate

The plane steel gate is widely used in water engineering.They have many advantages:its structure is briefness,it is convenient in making,installing and maintaining,the safety of plane gate is significant in hydraulic structures.When the plane gate is opened or part-opened,it needs to overcome the influence of water suction and the sedimentation on the web of the main beam.We solve this problem by the main beam web with drain hole(long circular).The large size hole reduce the safety performance of the plane gate and its main beam,and the design specifications do not have the specific requirements about the sectional size of the drain hole.Hence,analysis should be executed in the sectional size of the drain hole.Taking the design of a plane steel gate of a certain hydropower station,an analysis model is established by the finite element software.Base on the static method,the model with the reasonable size of drain holes is found,and by comparing and analyzing models of drain holes having various sectional sizes,change laws of various component stresses and deformation values can be obtained via calculation.The necessity of stiffening ring has been proved by calculation.The use of groove welding to join the stiffening ring is more secure.Base on the eigen buckling analysis method,an finite analysis model is calculated,the eigen buckling loads and buckling modes of long circular with web openings can be obtained.The connection between the size of web openings and the buckling load is performed based on a buckling coefficient.Finally,a fitting formula for providing a reference for the design work of the web openings is proposed,in which buckling coefficient and web opening coefficient.In this paper,the following conclusions can be drawn:stress and deformation volume of the plane gate components are reduced as the reduction of the sectional sizes of the drain holes.When the drain hole size is reduced,strength and stiffness of various components do satisfy the criteria set out in a design specification.The buckling coefficient of the openings web are reduced as the increment of the sectional sizes of the drain holes,indicating that the large size of the web openings can generate local buckling effect.Hence,strict mechanical analysis should be executed in designation such that the structural safety is directly influenced by the drain hole dimension of the plane gate.