Analysis And Studies On The Structure Of Combined Steel Tower Used For Bridge Construction

Structural designing of a super high,super wide,large tonnage combined steel tower used for construction in Nanning Bridge is taken as an engineering background in this thesis, and ANSYS general finite element program is used to set up a whole space analysis model of the tower, steel box arch ribs,cables and cordelles.By applying reasonable boundary conditions to the model, and considering the elastic restraint of cables and cordelles to the steel tower, internal force analysis and stability calculation are done for solving problems which take on in the tower structural designing. Also, finite element models analysis of three types tower joints are made to validate the rationality of local structures. The main content is as follows:First of all, this paper summarizes the construction methods of Concrete-filled Steel Tube (or steel box) Arch Bridge, and put special effect on inducing forms and structural constitutions of towers used in the cable erection and strayed knotting method. In addition, present and prospective application of hollow steel tube is discussed in this paper. In term of the project's factual instance, we put forward a set of ideas for the analysis and design of the combined steel tower used in the construction of Nanning Bridge.Secondly, in order to fit the installing of steel box ribs and steel box girders, the height of the tower is 128m and the width is 109m. The tower needs form a steady structure system with cables and cordelles. The tower holds highly P—Δeffect itself, cables and cordelles also take on nonlinear feature, so we consider the geometric nonlinearity effect when doing the whole tower system analysis. The results show that the intensity, stiffness and stability of the tower can satisfy the codes.Finally, by establishing finite element models, using elastic-plastic contact method in the analysis of tower's flange joints, and elastic-plastic large deflection method in the tubular joints with gusset plates, mechanical behavior, plastic range, joint deformation and ultimate strength of the joints are studied.