Research On Alternating Height Technology Of Frame Railway Bridge In Coal Mining Subsidence Area

In the construction of frame bridge in mining subsidence area,overhead technology is often used as the means to ensure the normal railway transportation.In this paper,using the method of theoretical calculation and numerical simulation,on the basis of frame bridge is put forward a kind of higher technology instead of traditional overhead structure alternately,heightening alternately for frame bridge technology,analysis the two,three,four layers framework box,at all stages of the alternation of continuous structure change rule under the influence of ground surface deformation,the following results:(1)In the subsidence area of coal mining,this paper first proposed the alternating high technology of frame bridge,which can ensure the normal railway transportation during the construction process.The box structure of the frame bridge can be built up to the fourth floor with a total height of 12 m.(2)Through research,it is found that in the process of alternating heightening of two-story,three-story and four-story structures,the influence of train rereading on structural stress is small,while the influence of ballast stacking and side wall height on structural stress is large.(3)In the process of alternating heightening of the box body of the frame bridge,the surface deformation has a great impact on the structural stress.When the surface inclination exceeds 5‰,the force on the box structure increases obviously with the increase of the slope,and the internal force on the side wall is most affected by the inclination.The negative curvature of the earth’s surface has a great influence on the force exerted on the floor,side wall and diaphragm.(4)the midspan position of the bottom plate of the box body structure,the connection position of the side wall and the bottom plate,the connection position of the side wall and the transverse diaphragm,and the end position of the transverse diaphragm are stress concentration areas.