ELASTIC BUCKLING OF WEB IN I-SECTION STEEL ARCH STRUCTURE SUBJECTED TO UNIFORMLY DISTRIBUTED RADIAL LOAD

The I-section steel arch structure has been applied widely in kinds of projects because of its beautiful shape,good mechanical property and simple manufacturing.However,the technical specification for steel arch structure has not been put forward yet,and the current codes and technical regulations for design of steel structures include no technology items for steel arch structure.Compared to the web of straight beam and column,the normal stress and shear stress also exist in welding I-section steel arch,but the most difference between them is the geometrical shape of the web,that for straight beam and column is rectangular while the one for welded I-section steel arch is arc,which makes the behaviors different.When an pin-ended arch is subjected to a radial load uniformly distributed around the arch axis,the load primarily produces uniform axial compression.The models simulating the I-section steel arch subjected to uniformly distributed radial load were built,with which the elastic buckling coefficients of single archy plates were obtained under the conditions of simply supported and fixedly supported loading side,and the related formulas were obtained through data fitting referencing the theory of elastic buckling of rectangle plate.Then,the elastic buckling coefficients and the related formulas of I-section steel arch were obtained considering the arbitrary degree rotational restraints of flanges to webs.