Analysis Of Continuous Rigid Frame Bridge Structure With Steel-Concrete Composite Beams In The Middle Span

Since the bridge is only built of a single material,it is difficult to achieve a balance in terms of structural performance and economy,and the composite beam continuous rigid bridge has many advantages over the concrete continuous beam bridge in terms of self-weight and cost force form.Therefore,this paper uses RBF neural network selection to improve the general concrete continuous beam rigid bridge,and obtains the composite beam rigid bridge that replaces the middle and middle section of the span with the composite beam,and further mechanical analysis is carried out on the two bridges.Among them,the concrete continuous beam rigid structure bridge is constructed by cantilever pouring method;The symmetrical beams on both sides of the concrete continuous beam rigid pier roof with the middle section are composite beams are poured by cantilever beams,the side spans are poured with full hall supports,and the middle composite beam section is directly hoisted.After viewing the calculation results of typical cross-sectional bending moment,stress and displacement in the construction bridge forming process,the span diameter and beam height of the intermediate section composite beam were optimized.Through the above work,this paper mainly draws the following main conclusions:（1）The RBF neural network is trained,and the predicted cross-section size of the composite beam is obtained by taking the actual bridge information in the engineering background as input.The cross-section design of the composite beam was completed,and the model analysis of the designed composite beam bridge was carried out in the subsequent chapters,and the correctness of the model was verified.（2）The comparative analysis of bending moment,normal stress and displacement in the construction stage of the two bridges verifies the correctness of the bending moment distribution of the two bridges,and the conclusion that the positive stress and displacement meet the requirements of the specification are obtained,and the reasons for the difference in bending moment,normal stress and displacement are further discussed.（3）Through the establishment and calculation of mechanical model,it is proved that changing the ratio of composite beam segment to the middle span diameter6)₁ and the bending stiffness of the composite beam section can affect the bending moment value of any section of the bridge,and the modeling of concrete continuous beam rigid bridge with different6)₁ values and different height of the composite beam in the middle is completed,and the optimal length and height of the middle span composite beam are obtained after comparative analysis.