New Guangzhou Railway Station, Dongping Suidobashi By Force Characteristics And The Bridge Deck System Is A Comparative Study

The Dong Ping Bridge at new Guangzhou station is a continuous three main steel truss through arch bridge with span arrangement (99+242+99)m. The bridge allows four lines high-speed railway. The structure of steel orthotropic deck was used in the railway deck.The mechanical behaviors of this bridge deck structure is complex and it is not usually adopted in high-speed railway bridges at home and abroad.The mechanical behaviors of the main truss and the floor system of the Dong Ping Bridge were studied systemically in this thesis.Main work of this thesis is as follows:1. The mechanical characteristics analysis of DongPing bridge under dead load and worst-live load has been studied using the space finite element method. The results of the analysis show that the working condition of the bridge is reasonable and the strength and stifmess requirements were satisfied.2. The transfer paths and the transfer ratio of the deck load,as well as the factors influencing the load transfer ratio have been studied.The main conclusion is as listed. The the load transfer ratio is related to the relative stifmess of the lower chords,nodal cross beems and panel cross beems. For the DongPing Bridge,the load transfered by nodal cross beems is about 30～38%,and the load transfered by panel cross beems is about 62～70%.3.The deck load allocation of the three main trusses had been studied. The results show that the transverse allocation ratio among three trusses reached about 1:1:1 near the middle of the span where the load allocated to middle truss was a little more than that of the edge trusses,and the ratio was about 1:3:1 near the support where the load allocated to middle truss was much more than edge truss under the deck load when the stiffness of the three trusses is close .Fortunately,most of the deck load near supports transfer directly into the supports and do not cause large deformation of the main trusses.4.The effects of the concrete slab on the bridge stiffness and mechanical behaviors has been studied. The main results are as listed. The concrete slab increased the vertical stiffness and lateral stiffness of the bridge by 10% and 13% respectively and do not cause much difference of the mechanical behaviors of the main trusses. As the thickNess of the concrete slab enlarged, the internal forces and stresses of the nodal cross beam in the floor system increased, while the internal forces and stresses of stringer,longitudinal rids, panel cross beems decreased.5.The effects of geometrical parameters of floor system on the whole bridge stress are discussed. The results are as followed.As the thickNess of the steel bridge deck slab enlarged,the stress of structural members of floor system decreased. As the thickNess and height of U-shape rib enlarged, The stress of concrete ballast channel plate, steel bridge deck slab, stringers,longitudinal rids and lower chords decreased while the stress of nodal cross beams increased.The results of this thesis not only server the design of DongPing Bridge but also provide references for other similar structures.