Analysis and Design of Complex Steel Structure of High-Rising Sightseeing Tower

The sightseeing tower, with its high structural height and slender shape, greatly improves tourists’ visual experience, but it also brings great challenges to structural design. By analyzing a complex high - rise sightseeing tower project, the characteristics and difficulties are introduced in terms of steel structure design of sightseeing tower. The total height of the sightseeing tower is 204. 4 m, which mainly includes four parts: podium, tower body, tower and amusement equipment at the top of the tower. Its functions include shopping malls, property service, revolving restaurants, sightseeing platforms and amusement facilities. The main structure of the steel tower adopts the form of steel structure cylinder, and the cylinder body is composed of concrete filled steel tube columns and steel bracings. The plane of the cylinder body is octagonal, and eight concrete-filled steel tubular columns and cross-story X-shaped braces are vertically arranged along the octagonal periphery as the main lateral force resistance system.
On the basis of introducing the overall structural system and functional distribution, the paper expounds the structural design scheme in combination with the characteristics and difficulties of each part of the structure. The height-width ratio of the main tower structure of the sightseeing tower is large, the tower has a large diameter and a high position, which enlarges the adverse effect of large height-width ratio. According to this characteristic, four outrigger trusses were arranged at the bottom of the tower body, and the elevation of the connection between the outrigger trusses and the steel column was determined through comparative analysis, which effectively reduced the adverse effect of large height-width ratio of the main tower structure; For the stiffness weakening caused by large openings in the floor, horizontal steel braces were arranged in the floor, and a long truss resisting horizontal force was formed together with floor steel beams; The bottom layer of the tower was set as the transfer truss layer to realize the large cantilever of the tower, and the cantilever truss members were all made of H-shaped steel; In order to effectively anchor the space shuttle amusement equipment at the top of the sightseeing tower, a transfer truss was arranged at the bottom of the space shuttle support to directly transfer the load to the concrete-filled steel tubular column of the tower; Special steel beams were arranged to support the revolving restaurant equipment, and the structural height difference caused by the height of rotating equipment was solved by adopting the methods of variable truss height and variable cross-section height beams respectively.
Using finite element software, modal analysis, wind load and earthquake action analysis, structural deformation and stress analysis were carried out on the sightseeing tower structure, and fine finite element analysis was conducted on the key joints in the structure, such as the connections between the outrigger trusses and the podium. The analysis results show that the performance indexes such as vibration mode and period of the structure, lateral deformation of the structure under wind load and earthquake, vertical deformation of the structure and the bearing capacity of members all meet the requirements of the code; Cast steel joints were completely in the elastic range and meet the design requirements; Wind load is the control load in the structural design of the sightseeing tower, and the earthquake action has little influence.