Structural Stability And Static Analysis Of Left And Right Asynchronous Construction Of Steel Box Tied Arch Bridge

The steel box tied arch bridge has many advantages such as fast construction speed,modular prefabrication,reducing the weight of the bridge superstructure,reducing the height of the bridge building,and beautiful appearance.Once proposed,it is widely used and sought after by engineers and researchers from various countries.With the development of my country's economy in recent years,people have deepened their understanding of bridge aesthetics,and a large number of steel box tied arch bridges have appeared in cities.With the further application of the bridge type,the construction personnel found that urban bridges often have special geographical locations,construction conditions are completely different from highways,and roads cannot be completely closed.Therefore,in actual construction,modular prefabricated,on-site asynchronous construction splicing,etc.are often used.The construction method puts forward higher requirements on the stress,displacement,stability and position of the welding seam during construction.In this paper,based on the Linhe City Zhuhe Bridge(asynchronous construction of the east-west through the steel box tie-bar arch)as the project,the Midas civil and Midas fea were used to establish the full bridge and detail models respectively.Research and analysis of mechanics and stability.In the study of the construction process and the operation of the completed bridge,the Midas civil space slab element model is established to explore the mechanical properties of the structure: the static behavior research structure changes the stress and displacement in each construction stage,and the actual value is compared with the theoretical value.To determine whether the structure is built according to the predetermined requirements;the stability performance study the stability safety factor of the structure in each construction stage,and determine the stability of each construction stage through the size of the stability safety factor;in the research process of orthotropic bridge deck,use Midas fea Modeled with civil two finite element software,through the comparison of the two models,to judge the accuracy of the finite element analysis results,and through the stress analysis results to find a reasonable location of splicing welds.In the process of static behavior research,the article expounds the research results of static behavior of related structures.On this basis,the midas civil slab element model is established to analyze the static behavior of bridges at various construction stages.The results show that: bridge stress,The deformation value agrees well with the theoretical value,the construction error of the structure is small,and the structure can meet the predetermined mechanical performance index.In the process of stability research,the article summarizes the sensitivity characteristics of similar structures and describes the classification of stability problems and the finite element solution of stability problems.Through the establishment of the plate unit model,the stability characteristics of the structure in this paper are explored.The analysis shows that: in the operating state,the stability safety factor of the structure meets the specification requirements;in the half-width open state,the full frame support needs to be welded with the main beam as a whole to meet the structure.Stable safety requirements;Use the control variable method to study the magnitude of the influence of a component in the bridge on the overall stability of the bridge.Through the magnitude of this magnitude,the errors in the construction process are controlled differently.Studies have shown that: in the sensitivity analysis of the stability factor of safety of the structure,the increase in the stiffness and number of wind braces has a positive effect on the stability of the structure;the increase in the ambient temperature and the increase in the stiffness of the tie bar have a negative impact on the stability of the structure;the arch rib The change law of inclination and stability is quite different from related research.For the bridge type studied in this paper,when the arch rib is perpendicular to the main beam,the stability safety factor is the largest.When researching the orthotropic bridge deck,the accuracy of the slab element simulation was verified by comparing the results of the Midas fea model and the Midas civil model;the finite element simulation of the real bridge segment model was used to explore the segment model Stress distribution characteristics;by moving the load tracker function,greatly reducing the workload of finding the most unfavorable load;introducing the concept of expectation,taking into account the stress size and load distribution frequency,and more accurately exploring the reasonable position of the splicing weld.