Jingguang Center

Jingguang Center is located in the East Third Ring Road in Beijing. The main tower is 206.8m high, with a 90-degree fan shape, 3 floors underground and 54 floors above ground. The underground part is a steel-concrete hybrid structure, the above-ground part is a steel structure, and the structural system is a steel frame-core tube, located in the 8-degree seismic fortification area.

The renovation of the main tower of Jingguang Center mainly includes:

1. Adjust the building function and division of the first underground floor to the seventh floor above ground;

2. Demolition of the interlayer originally located between the 1st and 2nd floors, resulting in changes in structural load distribution and changes in floor openings;

3. Remove the floor slabs located in the hotel lobby on the 2nd and 3rd floors;

4. Partially increase the floor slab on the 5th floor, adjust the original stair layout and add stairs and elevators;

5. A large area of green planting area is added to the outdoor ground of the first floor.

Concrete reinforcement

(1) The actual scene of the site after the construction of the steel plate reinforcement is shown in the figure.

(2) Increase the height of the section: Since a large area of greening is added to the outdoor part of the first floor, the load increases more, and the bearing capacity of the main beam of the structure needs to be improved. Therefore, the method of increasing the section is mainly used for reinforcement.

(3) Increase the section width: When there are unmovable electromechanical pipelines, walls, etc. under the structural beam, which affect the construction of the beam to increase the section, the bearing capacity of the structural member can be improved by increasing the section width.

(4) Only increase the reinforcement without increasing the section size. The project has high requirements for clearance. When the beam needs to increase the bearing capacity and the beam height cannot be increased, the reinforcement method of only adding steel bars at the bottom of the structural beam without increasing the cross-section is adopted. The newly added steel bars are connected with the original steel bars by short bars welding

(5) Increase the section height and increase the section width. For vertical structural members with high requirements on the bearing capacity of the members, at the same time increase the width and height of the section to improve the flexural and shear bearing capacity of the members, so as to avoid the occurrence of insufficient shear bearing capacity.

(7) Outsourcing steel reinforcement: When the shear bearing capacity of the structural column is insufficient, the shear bearing capacity of the component can be improved by wrapping steel plates on the outside of the column section. The steel plates need to be welded during construction, so the construction of the steel glue for the welded part needs to be completed after the welding is completed, so as to avoid the damage to the steel glue caused by the high temperature during welding.

8) Increase secondary beam reinforcement. There are two types of reinforcement for adding secondary beams: adding concrete beams and adding steel beams. Including increasing the bearing capacity of the floor, adding structural columns on the plate, adding secondary beams next to larger openings, and changing the force transmission path of the components by adding secondary beams to achieve the effect of strengthening the main beams and columns.

(9) Increase the wall reinforcement: Due to the increase in the upper load, the punching shear bearing capacity of the raft under some columns is insufficient. The punching force on the raft is shared by adding a wall in the middle of the column.