Study On Splicing Method Of New And Old Hollow Slab Beam In Reconstruction And Extension Of Expressway

Because of the difference of stiffness and connection mode between the new and the old hollow slab beam,the whole performance and stress characteristics of the bridge structure are greatly affected.In order to make the new and old hollow slab beams have good integrity and clear stress mechanism after splicing,it is necessary to analyze the different connection modes.In this paper,the stress characteristics of prestressed hollow slab beam with 13 m span are studied by numerical simulation.The main contents and main conclusions of this paper are as follows:(1)Through the finite element simulation and analysis of the new and old hollow slab beams with different rigidity spliced under three kinds of splicing conditions: no connection,wet joint connection,wet joint + diaphragm beam,the reasonable thickness of bridge deck pavement and the distance between beam and plate are obtained under different connection conditions(2)By comparing the difference of stress,displacement and displacement between two adjacent hollow slab beams with different stiffness,the influence of the thickness of pavement and the space between the new and old Hollow Slab Beams on the mechanical properties of the new and old slab is obtained..(3)The reasonable thickness of pavement layer and the reasonable space between new and old hollow slab beam under each connection mode are given according to different mechanical properties and Effects of Construction and other actions.(4)Through the comparison of the three connection methods,it is suggested that the non-connection method should not be adopted in the project,and the suitable range of road grade is given for wet connection and wet connection + diaphragm beam connectionBased on the modeling and analysis of 13 m span hollow slab-girder bridges with different connection conditions,this paper provides a theoretical basis for the connection mode of the same span hollow slab-girder bridges in the later period,and has guiding significance for the 13m span hollow slab-girder bridges with different connection conditions.