Analysis Of The Efficiency Of Large Span Structures And Research On Cable Structure Design

Since the advent of architecture,mankind has been pursuing the possibility of making it reach a larger span.Large span buildings and the technology of large span structure are one of the important signs of a national building technology level.This paper is guided by the engineering problem of large span structure,aiming to be helpful for the structure design.The mechanism of the large span structure is studied,and the related problems of the cable structure are discussed based on a project case.This paper may provide reference and guidance for solving the design problems of large span structures,especially cable structures.The main work and results are as follows:1)The efficiency of large span structures is discussed.According to the characteristics of the moment generated by the vertical load,the large span structures can be divided into three categories,namely beam structure,truss structure and cable-arch structure.Theoretical analysis and case analysis show that the cable-arch structure has the highest efficiency in resisting the moment generated by the vertical load,the truss structure is the second,and the beam structure is the lowest.The advantage of the efficiency of the cable-arch structure can be explained intuitively from the component stress level,the internal-external force level and the force arm level.2)The stiffness of the cable is studied.The stiffness of the cable structure is related to the material,the connections and constraints of the components,the geometry of the components,and the internal forces of the structure.The stiffness of the cable includes lateral stiffness and axial stiffness.The lateral stiffness of the cable is composed of small displacement linear stiffness,geometric stiffness and large displacement stiffness.Theoretical analysis shows that there is a transformation relationship between the three kinds of stiffness during the cable deformation process.The axial stiffness of the cable is affected by the sag of the cable.It is demonstrated that the axial stiffness of the cable has an influence on its lateral deformation by comparing the deformation of the cable under different load modes.When the load mode of the cable changes,the lateral deformation of the cable will increase significantly.3)The key issues of cable structure design are discussed based on a project case.The characteristics of cable structure in terms of safety,applicability and economy are analyzed.The design difficulties and solutions of cable structure in terms of the force transmission path,the overall redundancy,the overall stiffness and the stability of the compression bars are discussed.It is difficult for structural engineers to establish the model in the process of cable structure calculation.Parametric modeling is an effective means to deal with this difficulty.The principle,process and advantages of parametric modeling are discussed based on the project case.4)The construction complexity that needs to be considered in the cable structure design process is discussed.It is extremely important to consider the complexity of construction in the design of cable structure.The construction complexity factors are analyzed based on the project case,and the methods to solve the construction complexity problems are proposed.The key construction problems in the project case were discussed,and the conclusion that construction steps should ensure the realization of the design is achieved.