Strengthening Concrete Cruise Center

During the main construction stage of the Three Gorges Cruise Tourist Center, partial structural load adjustments and functional upgrades were implemented for the building. To meet the updated structural bearing capacity, crack resistance and durability requirements under large passenger flow loads, local beams and floor slabs of the tourist center required structural reinforcement.

According to on-site structural detection and design requirements, a composite and differentiated strengthening system was adopted for floor slabs and frame beams: 

frame beams are strengthened with bonded steel plates; floor slabs adopt three targeted strengthening schemes, including single carbon fiber reinforced polymer (CFRP) reinforcement, single bonded steel plate reinforcement, and combined CFRP & steel plate composite reinforcement, which fully adapts to the different span specifications and load-bearing conditions of on-site floor slabs.

Beam Strengthening: Full-scale Bonded Steel Plate Reinforcement

The primary and secondary frame beams bear large concentrated loads and bending-shear combined forces. External bonded steel plate reinforcement is adopted for all beams to improve overall rigidity and bearing capacity. Steel plates are pasted on the beam bottom to enhance flexural bearing capacity, and U-shaped steel hoops are installed on beam sides for shear resistance reinforcement. The steel plates and concrete form an integrated stress system through high-strength structural epoxy adhesive, which features high rigidity, stable bearing capacity improvement and excellent overall working performance, meeting the long-term heavy-load service requirements of public tourist buildings.

Slab Strengthening

In view of the different spans, thicknesses and load grades of on-site floor slabs, three scientific and targeted strengthening methods

(1) Single CFRP Reinforcement for Floor Slabs: Applied to conventional medium and small-span floor slabs with general load growth. Carbon fiber fabric features ultra-light weight, high tensile strength and thin thickness, which will not increase the self-weight and floor height of the original structure. It can effectively improve the flexural and crack resistance of floor slabs, inhibit concrete crack propagation, and enhance the waterproof and anti-corrosion performance of slab concrete, with outstanding advantages of convenient construction and no space occupation.

(2) Single Bonded Steel Plate Reinforcement for Floor Slabs: Adopted for partial large-span and partial heavy-load floor slabs requiring high rigidity improvement. The bonded steel plate significantly improves the overall stiffness and local bearing capacity of the floor slab, reduces structural deflection, and solves the structural deformation problem of large-span slabs under long-term uniform load, ensuring the structural flatness and service safety of the passenger distribution area.

(3) Composite CFRP & Steel Plate Reinforcement for Floor Slabs: Used for key super large-span and key stressed floor slabs with strict load and deformation control requirements. The complementary advantages of the two technologies are fully utilized: steel plates provide high rigidity and strong bearing support, while CFRP restrains micro-cracks and resists fatigue damage. The composite system greatly improves the comprehensive mechanical performance of the floor slab, meeting the ultra-high safety standard of key functional areas of the tourist center.

The project adopts a combination of three floor slab reinforcement schemes matching with beam steel bonding reinforcement, realizing precise reinforcement according to different stress characteristics of different structural components. It avoids the waste of engineering cost caused by unified excessive reinforcement and eliminates potential safety hazards caused by insufficient local reinforcement, with high engineering pertinence.