Discussion on the Structural Design of the New Shenzhen Cultural Center

The new Shenzhen Cultural Center has complex architectural shape and many internal space changes, with a large cantilevered space of more than 21 meters. In order to ensure reasonable lateral and torsional stiffness of the whole structure, 8 reinforced concrete tubes are set up in staircase and elevator of the building, which form the frame shear wall structure with the surrounding frame columns. However, due to the changes in the inner and outer space of the building and the special requirements in the function, the structure has many irregular items and complex substructures. For example, the opening rate of the typical floor of the cultural museum is more than 32% , due to the large functional difference between the various areas in the museum and the connection between the areas only through the indoor corridor, the actual situation of the floor is not consistent with the rigid floor assumption. At this time, how to evaluate the deformation index of the structure and the ability of the floor to coordinate the deformation becomes a major difficulty in the design. The cultural center is divided into three areas, namely, the core tube group area on the left side, the core tube group area on the right side and the large-span steel structure area on the east side. The typical observation points in the three areas are selected to investigate the deformation of the observation points under earthquake action, and further judge whether the floor has the ability to coordinate the deformation differences among the three areas. The scheme of the large cantilevered area is compared, and the stress analysis of the floor members connected to the upper chord of the overhang truss is carried out. The force transfer between the truss and the core tube can be ensured when the structure is subjected to rare earthquake and the floor in the weak connection position is damaged and the floor stiffness is degraded or even completely withdrawn from work. The function of the building on the east side requires large column span and floor height. Typical column distance is 8. 4 m×16. 8 m, and steel columns can only be arranged in L4-L8 floors, and Y-shaped slanted columns can be set between B1-L4 floors to support the upper steel columns. The ability of Y-shaped slanted column to independently bear overturning load is analyzed when gravity is transferred. At the same time, Y-shaped slanted column is 3-4 stories cross-layer column. Whether it can meet the requirements of stable bearing capacity and resistance to continuous collapse is a key and difficult point to discuss. When the structural stiffness index ( such as the inter-story displacement angle) is investigated, the deformation value of key measuring points can be captured by sectional statistics according to the structural stress situation, and the ability of the floor to coordinate deformation can be comprehensively evaluated. For the indoor bridge and the weak connection position of the floor, the envelope design is carried out by establishing the separating model, and the floor reinforcement is strengthened. By setting steel beams, columns and inclined rods in the shear wall supporting the large cantilevered truss, the three-dimensional tube structure is formed, and the influence of floor stiffness degradation on the force and deformation of the components between the large cantilevered truss and the tube structure is fully considered. The analysis results show that the large cantilevered truss and the tube structure can meet the checking calculation. The ability of Y-shaped slanted column to independently bear overturning load is weak. In design, the floor connection between slanted column and core tube group is strengthened, and the stress ratio of pull beam between slanted column and core tube is strictly controlled. When designing the Y-shaped slanted column, the nonlinear stability bearing capacity analysis should be carried out considering the initial defects of the component, and the stable bearing capacity reserve of the slanted column should be defined. By using linear static alternate path method, the slanted column structure can be judged to meet the requirements of continuous collapse resistance. The typical joint of the large cantilevered truss and shear wall and the transfer joint of steel reinforced concrete truss are selected as the research object, and the corresponding joint strengthening structure is proposed.